ALBERT

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Sai Huang, Zhihao Wang, Qi Zhu, Xiaofei Shi, Xuejiao Wang, Xiaodong Li, Xudong Sun, Ji-Guang Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉RE(OH)〈sub〉2.94〈/sub〉(NO〈sub〉3〈/sub〉)〈sub〉0.06〈/sub〉·〈em〉n〈/em〉H〈sub〉2〈/sub〉O nanosquares were first employed as template to synthesize YVO〈sub〉4〈/sub〉:Ln luminescent crystallites (Ln = Eu, Sm, and Dy) via hydrothermal nanoconversion in the presence of NH〈sub〉4〈/sub〉VO〈sub〉3〈/sub〉. Product properties and the course of phase/morphology evolution were characterized in detail by XRD, SEM, TEM, FT-IR, TG, and optical spectroscopy. It was clearly demonstrated that the nanosquares templated vanadate crystallization, owing to structure similarity, but was accompanied by subsequent dissolution and reprecipitation. The resultant vanadate phosphors, mostly in the form of bundles containing platelike and fibrous crystallites, exhibited strong red emission at ∼618 nm for Eu〈sup〉3+〈/sup〉, orange-red emission at ∼604 nm for Sm〈sup〉3+〈/sup〉 and greenish yellow emission at ∼575 nm for Dy〈sup〉3+〈/sup〉 upon exciting the VO〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 ligand. Dehydration at 500 °C further improved the emission by ∼2.5 times for Eu〈sup〉3+〈/sup〉 and ∼1.5 times for Sm〈sup〉3+〈/sup〉 and Dy〈sup〉3+〈/sup〉. The Eu〈sup〉3+〈/sup〉 (5 at%), Sm〈sup〉3+〈/sup〉 (1 at%) and Dy〈sup〉3+〈/sup〉 (1 at%) activators were analyzed to have quantum yields of ∼48, 9 and 16% and color coordinates of around (0.65, 0.33), (0.60, 0.39) and (0.38, 0.43) for their luminescence, and fluorescence lifetimes of ∼1.52, 1.40 and 0.89 ms for their dominant emissions, respectively. It is also interesting to find out that replacing only 15% of the total OH〈sup〉−〈/sup〉 and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 anions in the template by VO〈sub〉4〈/sub〉〈sup〉3−〈/sup〉 produced ∼20 times stronger Eu〈sup〉3+〈/sup〉 luminescence, indicating that VO〈sub〉4〈/sub〉〈sup〉3-〈/sup〉→ Eu〈sup〉3+〈/sup〉 energy transfer is very efficient. The protocol would be extendable to other types of functional rare-earth compounds.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339719-fx1.jpg" width="245" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Chunmu Guo, Qinghua Tian, Li Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nanostructure of titanium dioxide (TiO〈sub〉2〈/sub〉) has gained extensive attention in anode material field of lithium-ion batteries (LIBs) owing to its outstanding structure stability and improved safety over graphite. Herein, facilely controllable synthesis of interestingly spindle TiO〈sub〉2〈/sub〉 nanograins has been achieved by a one-pot hydrothermal and subsequent calcination approach, it is demonstrated that the grain size has a great effect on the electrochemical lithium storage kinetics of as-synthesized TiO〈sub〉2〈/sub〉 nanograins. As a result, the as-prepared TiO〈sub〉2〈/sub〉-0.05M with much smaller size exhibits greatly improved lithium storage performance, delivering a capacity of 120.5 mAh g〈sup〉−1〈/sup〉 after even 1000 cycles.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Xi Cheng, Shi Wei Xu, You Ming Lu, Shun Han, Pei Jiang Cao, Fang Jia, Yu Xiang Zeng, Xin Ke Liu, Wang Ying Xu, Wen Jun Liu, De Liang Zhu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zn〈sub〉1-x〈/sub〉Cd〈sub〉x〈/sub〉O films with different Cd contents obtained by controlling the growth oxygen pressure (O〈sub〉p〈/sub〉) were deposited on both c-sapphire (Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉) substrates and p-GaN substrates, by means of the pulsed laser deposition (PLD) method. Photoluminescence (PL) measurement revealed that the variation of O〈sub〉p〈/sub〉 influenced the amount of Cd doping into Zn〈sub〉1-x〈/sub〉Cd〈sub〉x〈/sub〉O films deposited on Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉, leading tunable luminescence from the ultraviolet (UV) to blue emission extended to the green band. Then all the fabricated n-Zn〈sub〉1-x〈/sub〉Cd〈sub〉x〈/sub〉O/p-GaN heterojunction possessed good ohmic contacts and exhibited typical rectifying characteristic of the diode. Indeed, the high luminescence from the ZnCdO layer could be attained by inserting a MgO insulator to the heterojunction interface. The fabrication of tunable n-Zn〈sub〉1-x〈/sub〉Cd〈sub〉x〈/sub〉O/p-GaN heterojunction light-emitting diodes is available which was supported by the results of electroluminescence (EL) experiment.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Dina V. Deyneko, Ivan V. Nikiforov, Bogdan I. Lazoryak, Dmitry A. Spassky, Ivan I. Leonidov, Sergey Yu. Stefanovich, Daria A. Petrova, Sergey M. Aksenov, Peter C. Burns〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel red emitting phosphors Ca〈sub〉8〈/sub〉MgSm〈sub〉1–〈em〉х〈/em〉〈/sub〉(PO〈sub〉4〈/sub〉)〈sub〉7〈/sub〉:〈em〉x〈/em〉Eu〈sup〉3+〈/sup〉 with whitlockite-type structure were prepared by a high temperature solid-state reaction in air. Powder X-ray diffraction (PXRD), photoluminescence spectra, and fluorescence decay were used to characterize the structure and luminescence properties. All samples were found to have the expected rhombohedral structure with 〈em〉R〈/em〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉3〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉〈em〉c〈/em〉 space group. The non-polar space group is also confirmed by a photoluminescence study. This space group allows forbidden transitions for Eu〈sup〉3+〈/sup〉. The presence of only one Shtark component in 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉–〈sup〉7〈/sup〉F〈sub〉0〈/sub〉 confirms the presence of only one non-equivalent site containing Eu〈sup〉3+〈/sup〉 ions. The high intensity of the transition ratio 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉–〈sup〉7〈/sup〉F〈sub〉2〈/sub〉/〈sup〉5〈/sup〉D〈sub〉0〈/sub〉–〈sup〉7〈/sup〉F〈sub〉1〈/sub〉 establishes the strongly disordered environment of the Eu〈sup〉3+〈/sup〉 ions. Thus, 〈em〉M〈/em〉1–〈em〉M〈/em〉3 sites in the host matrix are occupied by Ca〈sup〉2+〈/sup〉, Sm〈sup〉3+〈/sup〉, and Eu〈sup〉3+〈/sup〉 ions, whereas 〈em〉M〈/em〉5 is fully occupied by Mg〈sup〉2+〈/sup〉. The optimal concentration was found with 〈em〉x〈/em〉 = 0.75 in Ca〈sub〉8〈/sub〉MgSm〈sub〉1–〈em〉х〈/em〉〈/sub〉(PO〈sub〉4〈/sub〉)〈sub〉7〈/sub〉:〈em〉x〈/em〉Eu〈sup〉3+〈/sup〉 phosphors. The emitting of Sm〈sup〉3+〈/sup〉 was depressed due to the high intensity of Eu〈sup〉3+〈/sup〉 luminescence; however, the contribution of Sm〈sup〉3+〈/sup〉 is manifested in the energy transfer process and shift of CIE coordinates. Furthermore, the CIE chromaticity coordinate of 〈em〉as-prepared〈/em〉 Ca〈sub〉8〈/sub〉MgSm〈sub〉0.25〈/sub〉(PO〈sub〉4〈/sub〉)〈sub〉7〈/sub〉:0.75Eu〈sup〉3+〈/sup〉 (〈em〉x〈/em〉 = 0.650; 〈em〉y〈/em〉 = 0.345) is close to the standard red-emitting point (〈em〉x〈/em〉 = 0.67, 〈em〉y〈/em〉 = 0.33). The experimental data indicate that Ca〈sub〉8〈/sub〉MgSm〈sub〉1–〈em〉х〈/em〉〈/sub〉(PO〈sub〉4〈/sub〉)〈sub〉7〈/sub〉:〈em〉x〈/em〉Eu〈sup〉3+〈/sup〉 upon excitation by near-UV radiation is a promising red phosphor for white-light-emitting diodes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339999-fx1.jpg" width="131" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Wanwu Ding, Chen Xu, Xingang Hou, Xiaoyan Zhao, Taili Chen, Wenjun Zhao, Tiandong Xia, Jisen Qiao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The new type of Al-Ti-C-La master alloy was prepared by commercial pure Al, Ti powder, graphite powder, Al powder and La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 powder by aluminum melt in-situ reaction method. The microstructure and the effect on commercial pure aluminum of Al-Ti-C-La master alloy have been studied by means of X-ray diffraction (XDR), scanning electron microscopy (SEM) equipped with energy-dispersive spectrometry (EDS). The synthesis thermodynamics and kinetics of Al-Ti-C-La master alloy were analyzed. The experiment shows that Al-Ti-C-La master alloy is composed of Al, Al〈sub〉3〈/sub〉Ti, TiC and Ti〈sub〉2〈/sub〉Al〈sub〉20〈/sub〉La. The refining performance of the prepared Al-Ti-C-La master alloy is obviously better than that of Al-Ti-C master alloy when the addition of rare earth oxide La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 is 10 wt% and the preparation temperature is 930 °C. The analysis of thermodynamic calculation and the process of kinetics demonstrate that, in the preparation process of Al-Ti-C-La master alloy, firstly, Al reacts with Ti to produce Al〈sub〉3〈/sub〉Ti, C reacts with Ti and Al〈sub〉3〈/sub〉Ti to form TiC based on the aluminothermy reaction. Rare earth oxide La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and C powder react with Ti powder and O〈sub〉2〈/sub〉 in the air occur to generate CO, TiC, [La] atoms and LaC〈sub〉2〈/sub〉. [La] atoms adsorb on the surface of Al〈sub〉3〈/sub〉Ti to form the new rare earth compounds Ti〈sub〉2〈/sub〉Al〈sub〉20〈/sub〉La.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Changmeng Huan, Xinyue Zhao, Xiudi Xiao, Yuan Lu, Shuai Qi, Yongjun Zhan, Lingzhi Zhang, Gang Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, the V〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles (NPs) with ultrathin carbon shells were synthesized by a facile solvothermal process. The V〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs were about 30 nm and contained a carbon shell of about 2 nm thick. The V〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 NPs were homogeneously dispersed and loosely packed. When used as anode material, the V〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 core-shell NPs showed a reversible capacity up to 525 mA h g〈sup〉−1〈/sup〉 at 200 mA g〈sup〉−1〈/sup〉 over 200 cycles with good cycle stability and rate capability. The excellent electrochemical performance promotes its practical application in lithium-ion batteries.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Honghong Jin, Guang Sun, Bo Zhang, Na Luo, Yanwei Li, Long Lin, Hari Bala, Jianliang Cao, Zhanying Zhang, Yan Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel chain-like nanostructure of Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 was successfully prepared via a facile and reliable oxalate sacrificial template route, in which coralloid cobalt oxalate (CoC〈sub〉2〈/sub〉O〈sub〉4〈/sub〉·2H〈sub〉2〈/sub〉O) precursor was first obtained through a room-temperature precipitation method and then used as sacrificial template to prepare Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 by annealing at 500 °C. Au nanoparticles-decorated Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanochains were also prepared by soaking the CoC〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 precursor in Au〈sup〉+〈/sup〉 solution before the annealing process. The prepared samples were characterized by XRD, FESEM, TEM, and N〈sub〉2〈/sub〉 adsorption-desorption. Results indicated that the pure and Au-decorated Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanochains were constructed by several end-to-end connected nanoparticles, and their specific surface areas were 28.42 m〈sup〉2〈/sup〉/g and 37.39 m〈sup〉2〈/sup〉/g, respectively. The gas sensing properties of the prepared samples were tested and compared. It was found that after being functionalized with Au nanoparticles, the Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanochains showed an improved TEA sensing performance, such as lower optimal working temperature, higher response, and faster response and recover speed. In addition, the Au/Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 sensor can also give a good linearity in the TEA concentration range from 10 to 200 ppm and considerable stability within 7 weeks, suggesting its potential application for quantitative detection of TEA. The improved gas sensing mechanism of the Au/Co〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanochain was discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): V.A. Lysenko〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A modified version of the Sb-Sn phase diagram was proposed that includes both Sb〈sub〉2〈/sub〉Sn〈sub〉3〈/sub〉 and Sb〈sub〉3〈/sub〉Sn〈sub〉4〈/sub〉 compounds. Based on this modification, phase equilibria in the In-Sb-Sn system were calculated using a thermodynamic modeling approach. Thermodynamic models for the ternary liquid phase and solid solutions (SbSn) and (Sb〈sub〉2〈/sub〉Sn〈sub〉3〈/sub〉) were developed. The isopleths 〈em〉x〈/em〉〈sub〉Sn〈/sub〉 = 0.2, 0.5, 0.8, vertical sections 〈em〉x〈/em〉〈sub〉In〈/sub〉/〈em〉x〈/em〉〈sub〉Sb〈/sub〉 = 3:1, 1:1, 1:3, liquidus surface projection, and isothermal section at 473 K were calculated.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Hongyi Gao, Mengyi Jia, Keyi Dong, Liwen Xing, Xiao Chen, Dandan Jia〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Sisal-Like TiO〈sub〉2〈/sub〉/Graphene-Like Carbon Sheets (SL-TiO〈sub〉2〈/sub〉/GLCSs) composite was fabricated via a facile one-pot self-assembling route at a two-phase interface. The ingenious P123 was introduced to serve a dual function of carbon precursor and structure-directing agent, which first assembled at the water/oil interfaces and subsequently was in situ carbonized to GLCSs. Then the sisal-like TiO〈sub〉2〈/sub〉 grew gradually on the GLCSs along the preferred direction. This process shows several advantages such as simple processes, mild condition, low cost and good combination of SL-TiO〈sub〉2〈/sub〉 and GLCSs. The combination of SL-TiO〈sub〉2〈/sub〉 with GLCSs significantly helps the adsorption of substrates as well as promotes electron-hole pair separation, exhibiting good photocatalytic activity towards degradation of methylene blue (MB) compared to the pristine SL-TiO〈sub〉2〈/sub〉 and commercial P25. This strategy opens up new perspectives for fabricating novel composites of nanooxides/GLCSs.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Zhennan Liu, Naiqin Zhao, Chunsheng Shi, Fang He, Enzuo Liu, Chunnian He〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Three-dimensional (3D) carbon networks decorated with Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles as lightweight and broadband electromagnetic (EM) wave absorber were 〈em〉in-situ〈/em〉 prepared via a simple and large-scale method, combining freeze-drying and high-temperature calcination processes. SEM and TEM results show that 3D carbon network/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 (3DC/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉) composites have interconnected 3D porous carbon networks with submicrometer-sized macropores, and the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles are distributed uniformly on the 3D carbon networks. The EM wave absorption performance of 3DC/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 can be tuned by changing Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 contents. The 3DC/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 with about 38.2 wt% Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 exhibits excellent lightweight and broadband EM wave absorption property. The effective absorption bandwidth can reach up 5.95 GHz (11.2–17.15 GHz) at the thickness of 3.0 mm with only 20 wt% filler loading. The minimum RL of −37.8 dB was obtained at 6.95 GHz. The excellent EM wave absorption capability of 3DC/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 can be ascribed to good impedance matching, strong dielectric loss ability and unique 3D porous structure. This work demonstrates that the 3DC/Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 with light weight, broad absorption bandwidth and large-scale production potential can be a promising absorber for practical application.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339768-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Dan Zhou, Li-Ping Xue, Ning Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Transition metal phosphides are promising anode materials for next-generation rechargeable sodium-ion batteries due to the high theoretical capacities. However, the inherent low conductivity and large volume expansion of transition metal phosphides during the repeated sodiation/desodiation process critically hinder their practical applications. Herein, we immobilize Ni〈sub〉2〈/sub〉P nanoparticles robustly in porous carbon sheet networks via the pyrolysis and 〈em〉in-situ〈/em〉 phosphatization of poly(acrylic acid)-Ni(NO〈sub〉3〈/sub〉)〈sub〉2〈/sub〉 gel. The resulted porous network structure, high conductivity, robust chemical combination and space confinement effect of the Ni〈sub〉2〈/sub〉P-carbon composite offer the electrode not only rigid structural stability for volume expansion over long-term cycling, but also large specific capacity and fast Na〈sup〉+〈/sup〉/electrons transfer kinetics. As a consequence, the composite delivers a large initial discharge capacity (932 mAh g〈sup〉−1〈/sup〉 at 50 mA g〈sup〉−1〈/sup〉), a high rate capability (77 mAh g〈sup〉−1〈/sup〉 at 3500 mA g〈sup〉−1〈/sup〉), as well as a significantly enhanced long cycle-life (146 mAh g〈sup〉−1〈/sup〉 after 1500 cycles at 500 mA g〈sup〉−1〈/sup〉). The excellent Na-storage performance makes the synthesized Ni〈sub〉2〈/sub〉P-carbon composite a sound anode material for advanced rechargeable SIBs.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Yu Jun Yang, Weikun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work presents a novel method for the self-assembly of reduced graphene oxide (rGO) on nickel foam (NF) and the subsequent electrodeposition of hierarchical Ni-Co double hydroxide (NiCo-DH) nanosheets (NS) on rGO as a supercapacitor electrode. The self-assembly of rGO on NF is achieved by the direct reduction of graphene oxide at 50 °C. NF is not only used as the support of rGO but also the reducing agent for the reduction of GO. As the battery-type electrode material for supercapacitor, NiCo-DH supported on rGO modified NF (Ni-Co DHNS@rGO-NF) displays an ultrahigh areal capacity of 5.820 C cm〈sup〉−2〈/sup〉 at 20 mA cm〈sup〉−2〈/sup〉, a 100% coulombic efficiency and a 78% capacity retention after 2000 cycles at 100 mA cm〈sup〉−2〈/sup〉. An hybrid supercapacitor (HSC) is also assembled based on Ni-Co DHNS@rGO-NF as the positive electrode and active carbon (AC) as the negative electrode. The ASC exhibits a prominent energy density of 45.83 Wh kg〈sup〉−1〈/sup〉 at a high power density of 396.15 W kg〈sup〉−1〈/sup〉. The excellent electrochemical performance is attributed to the large surface area of the hierarchical NiCo-DH nanosheets array and the synergistic effect between Ni-Co DHNS and rGO.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Kodai Maeda, Satoshi Suzuki, Kyosuke Ueda, Tomonori Kitashima, Somesh Kr. Bhattacharya, Ryoji Sahara, Takayuki Narushima〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper reports the first study of the oxidative behavior of Si-containing Ti-6Al-4V alloys in air. The alloys were studied in the temperature range 910–1210 K for a maximum period of 518.4 ks, and their tensile properties at room temperature are reported. The addition of Si decreased the total mass gain during oxidation and enlarged the region in which the mass gain obeyed the parabolic rate law. The oxide scale mainly consisted of rutile and α-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 phases. The results of the XPS analysis suggest that in rutile, Si exists as both Si〈sup〉4+〈/sup〉 ions and SiO〈sub〉2〈/sub〉. First-principles calculations indicated that Si〈sup〉4+〈/sup〉 ions stably dissolved into the interstitial sites in rutile, which suppresses oxygen migration through rutile by decreasing the number of oxygen vacancies, thereby inhibiting oxide scale formation. The reaction layer consisting of Ti〈sub〉3〈/sub〉Al and α″ phases on Ti-1mass% Si alloy suppressed the dissolution of oxygen into the substrate, i.e., α-case formation. The ratio of mass gain in α-case formation to total mass gain during oxidation at 1010 K and 1110 K ranged from 0.077 to 0.42. The addition of Si to the Ti-6Al-4V alloy was effective in improving both its oxidative resistance and tensile strength.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339653-fx1.jpg" width="292" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Joo Sung Kim, Young Been Kim, Seung Ki Baek, Young Dae Yun, Sung Hyeon Jung, Sung Woon Cho, Cheol Hyoun Ahn, Hyung Koun Cho〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To maximize the advantages of thin-film-based TiO〈sub〉2〈/sub〉 photoelectrodes for transparent self-driven photoelectrochemical (PEC) reactions, we artificially designed a compositionally graded bi-layer compounds consisting of SnO〈sub〉2〈/sub〉 and TiO〈sub〉2〈/sub〉. This structure exhibited a vigorous photocatalytic activity, sufficient photovoltage, and long-term stability. A compositionally graded SnO〈sub〉2〈/sub〉/TiO〈sub〉2〈/sub〉 interface (G-SnTiO) for improved charge transport efficiency and sufficient photovoltage was derived by a solution process using simultaneous sintering after sol-gel coating the SnO〈sub〉2〈/sub〉/TiO〈sub〉2〈/sub〉 layers; the structure was verified by various analysis methods, such as transmission electron microscopy, energy dispersive X-ray spectroscopy, and secondary ion mass spectrometry. The high performance from the G-SnTiO structure was attributed to an effective charge separation from the formation of a heterostructure interface with reduced defects, resulting in a sufficient photovoltage for self-driving. To construct self-driven and sustainable overall cells without an external potential and considerable reduction in transparency, two-electrode PEC cells with a G-SnTiO photoanode and Cu〈sub〉2〈/sub〉O photocathode were fabricated with a regular hexahedron shape for a color degradation test of methylene-blue-incorporated electrolytes, and exhibited enhanced purification speed and robust durability.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339379-fx1.jpg" width="335" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Usama Bin Humayoun, Seok Bin Kwon, Syed Kamran Sami, Dae-Ho Yoon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Among various red phosphors, Mn〈sup〉4+〈/sup〉 activated fluoride hosts have received much attention due to their blue excitability and intense red emission. In this study we report a novel (NH〈sub〉4〈/sub〉)〈sub〉3〈/sub〉AlF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 phosphor, synthesized through a facile synthesis process avoiding high quantities of highly toxic HF acid. The synthesized host exhibit cubic structure in F-4 3m space group, with plenty of [AlF〈sub〉6〈/sub〉]〈sup〉3+〈/sup〉 octahedral sites. When activated with Mn〈sup〉4+〈/sup〉 the crystal structure is retained and the material exhibits characteristic excitation bands with maximum around 469 nm and intense red emission around 631 nm. Furthermore, the thermal gravimetric analysis revealed the stability of composition up to 250 °C. The phosphor however exhibits high sensitivity to increased temperature and showed sharp quenching of luminescence at elevated temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Rui Du, Du Yuan, Fei Li, Dongcheng Zhang, Shusen Wu, Shulin Lü〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study intends to offer a depth understanding on controlling the morphology of eutectic Mg〈sub〉2〈/sub〉Si by adding in-situ TiB〈sub〉2〈/sub〉 particles into 10 〈em〉wt〈/em〉% Mg〈sub〉2〈/sub〉Si/Al composite. The evolution of the microstructure and mechanical properties of Mg〈sub〉2〈/sub〉Si/Al composites with different TiB〈sub〉2〈/sub〉 particles addition from 1 〈em〉wt〈/em〉% to 5 〈em〉wt〈/em〉% is investigated and the mechanism is also discussed. The results show that coarse eutectic Mg〈sub〉2〈/sub〉Si phase can be refined and modified with the addition of TiB〈sub〉2〈/sub〉 particles, and the lattice coherence between them is also confirmed. Besides, the addition of TiB〈sub〉2〈/sub〉 particles can greatly enhance multiple mechanical properties of composites at the same time. With 5% TiB〈sub〉2〈/sub〉 particles addition, the modulus, yield strength and elongation of composites are improved 11%, 59% and 141% respectively compared with Mg〈sub〉2〈/sub〉Si/Al composites. Moreover, different addition of TiB〈sub〉2〈/sub〉 particles changes gradually the fracture behavior of composites from brittle fracture to quasi-cleavage fracture, and finally to entirely ductile behavior.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): S.S. Mani Prabu, H.C. Madhu, Chandra S. Perugu, K. Akash, R. Mithun, P. Ajay Kumar, Satish V. Kailas, Manivannan Anbarasu, I.A. Palani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Welding of shape memory alloys without deterioration of shape memory effect could vastly extend their applications. To retain shape memory behavior, a solid-state welding technique called friction stir welding was employed in this study. Austenitic NiTi alloy sheets of thickness 1.2 mm were joined at tool rotational speeds of 800, 1000, and 1200 rpm. Due to dynamic recrystallization, the grain refinement has occurred in the weld region. The tensile testing has shown superelastic plateau for the welds at 800 and 1000 rpm. The phase transformation behavior of different weld regions was studied in detail using differential scanning calorimeter. A marginal drift in transformation temperatures was observed in the weld. To understand the drift in phase transformation temperatures, finite element analysis was carried out with focus on temperature distribution during welding. Finally, time-dependent shape recovery of a FSW welded joint was studied and it was found that the original position was completely recovered after 27 s at a temperature of 65 °C.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881833874X-fx1.jpg" width="437" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Matthias Stacher, Gabriel R. Reisinger, Klaus W. Richter〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phase equilibria of Au-Ni-Si were investigated in the isothermal section at 700 °C using a combination of powder X-ray diffraction and quantitative phase analysis by SEM-EDX. Four vertical sections of the phase diagram at 10 at.% Au and at 15, 30 and 60 at.% Ni were studied by DTA. These data were combined with isothermal sections at 320° and 500° published earlier to develop a ternary reaction scheme and a liquidus surface projection. Fifteen ternary invariant reactions, a three-phase field maximum and a critical tie-line are proposed. The observed phase diagram is discussed regarding the possible use of Au-Si liquids for transient liquid phase (TLP) soldering of Nickel.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Yong Zhang, Jinming Guo, Jianghua Chen, Cuilan Wu, Karoline Sophie Kormout, Pradipta Ghosh, Zaoli Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bulk nanocrystalline alloys usually possess enhanced properties than their coarse-grained counterparts. Here, first-principles calculations and aberration-corrected transmission electron microscope (TEM) were employed to investigate the atomic-scale deformation mechanism of Cu-based alloys. The effect of alloying element concentration and temperature-induced solute distribution on the unstable stacking fault energy (γ〈sub〉usf〈/sub〉), stable stacking fault energy (γ〈sub〉isf〈/sub〉) and unstable twin fault energy (γ〈sub〉utf〈/sub〉) were calculated using a Fermi–Dirac distribution of solutes for 42 binary Cu-X alloys. At medium temperature (〉200 K) or low solute concentrations (〈15 at.%), the stacking fault energies calculated from the Fermi–Dirac model accord well with the available experimental and theoretical results. The deformation mechanism was then evaluated by α = γ〈sub〉isf〈/sub〉/γ〈sub〉usf〈/sub〉 and β = γ〈sub〉utf〈/sub〉/γ〈sub〉usf〈/sub〉, smaller α (β) favors an easier formability of extended dislocations (twins). Most subgroup VI-VIII metals in the periodic table can slightly increase the γ〈sub〉usf〈/sub〉, γ〈sub〉isf〈/sub〉 and γ〈sub〉utf〈/sub〉 of Cu, and have almost no influence on α and β. While main group and subgroup II-V elements can decrease γ〈sub〉usf〈/sub〉, γ〈sub〉isf〈/sub〉 and γ〈sub〉utf〈/sub〉 as well as the values of α and β. For alloying elements of Pd, Ag, Pt and Au, the values of α and β increase, suggesting a tendency of deformation mechanism from extended dislocations to full dislocations. Furthermore, high-resolution TEM (HRTEM) images of four representative nanocrystalline alloys (pure Cu, Cu-Fe, Cu-Ag and Cu-Zn) corroborates the prodiction with α and β as well as the empirical twinnability. The α and β remain almost the same as that of pure Cu when alloyed with Fe while they decrease with Zn, and the extended dislocations and twins were commonly observed for Cu, Cu-Fe and Cu-Zn. The α and β increased with Ag addition although the γ〈sub〉isf〈/sub〉 decreased, and the extended dislocations were barely observed for Cu-Ag sample. The theoretical and microstructural correlation provides insights into the deformation mechanism of Cu-based alloys.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Yongju Yoo, Yun Chan Kang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nb〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 materials based on intercalation reactions have been extensively studied as anode materials for lithium-ion batteries. Mesoporous Nb〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 microspheres with narrow size distribution are the ideal structure for achieving a high volumetric capacity. Mesoporous filled- and yolk-shell-structured (reported for the first time) Nb〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 microspheres are synthesized using a highly porous carbon template. The NbSe〈sub〉3〈/sub〉-C composite transforms into yolk-shell-structured Nb〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 microspheres by a one-step oxidation process. The filled microspheres having ultrafine crystallite size and high mesopore volume show better cycling and rate performances than the yolk shell microspheres. The discharge capacity of the filled microspheres at a current density of 1 A g〈sup〉−1〈/sup〉 is 124 mA h g〈sup〉−1〈/sup〉 in the 5000〈sup〉th〈/sup〉 cycle, and the capacity retention in the second cycle is 76%. The discharge capacity of the filled microspheres decreases by approximately 26% from 171 mA h g〈sup〉−1〈/sup〉 to 127 mA h g〈sup〉−1〈/sup〉 when the current density increases from 0.5 A g〈sup〉−1〈/sup〉 to 10 A g〈sup〉−1〈/sup〉. Particularly, the volumetric capacity of the filled microspheres at a high current density of 10 A g〈sup〉−1〈/sup〉 is 2.3 times higher than that of the yolk-shell-structured microspheres (filled ≈ 11.5 mA h cc〈sup〉−1〈/sup〉 vs. yolk ≈4.9 mA h cc〈sup〉−1〈/sup〉).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Dunya M. Babanly, Ziya S. Aliev, Qorkhmaz M. Huseynov, Salim M. Asadov, Solmaz N. Mustafaeva, Dilgam B. Tagiyev〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The phase equilibria in the ternary Tl-S-I system were investigated experimentally by means of powder X-ray diffraction (PXRD) and differential thermal analysis (DTA). Five isopleth sections, liquidus surface projection and room temperature isothermal section were constructed based on experimental data. 〈em〉dc〈/em〉-and 〈em〉ac〈/em〉-electric properties of the TlS and Tl〈sub〉6〈/sub〉SI〈sub〉4〈/sub〉 crystals were studied within the temperature and frequency ranges from 120 K to 300 K and from 50 kHz to 35 MHz, respectively. The hopping mechanism for charge transfer over the localized states near the Fermi level was established at low temperatures and high frequencies for these compounds. The density and energy scatter of the states which are located in the vicinity of the Fermi level as well as the average time and distances of jumps were estimated for the title compounds.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Marietta Seifert, Gayatri K. Rane, Siegfried B. Menzel, Steffen Oswald, Thomas Gemming〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A sufficient oxidation resistance of RuAl thin films is crucial for their application in high temperature sensors e.g. based on the surface acoustic waves principle. To improve the high temperature stability, an Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 or SiO〈sub〉2〈/sub〉 cover layer is added to protect the films from oxidation especially for application in air. The covered RuAl films are annealed at temperatures up to 900 °C under high vacuum and in air for 10 h. X-ray diffraction, cross section imaging and Auger electron spectroscopy are applied to reveal the suitability of the cover layers as oxidation barrier. While there is hardly any difference between the samples with or without cover layer after annealing under high vacuum, only the samples with SiO〈sub〉2〈/sub〉 cover are stable up to 800 °C in air.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339525-fx1.jpg" width="483" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): O.V. Maksakova, S. Simoẽs, A.D. Pogrebnjak, O.V. Bondar, Ya.O. Kravchenko, T.N. Koltunowicz, Zh.K. Shaimardanov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Multilayered ZrN/CrN coatings were produced by the cathodic arc physical vapor deposition (CA-PVD). Morphology, element distribution, structural and thermal properties were investigated. Microhardness and nanoindentation tests were conducted to study the mechanical properties of the coatings. The experimental results of scanning electron microscopy (SEM) revealed the cellular microrelief of the surface and well-defined multilayered architecture of the coatings. Energy dispersive spectroscopy (EDS) provided the chemical characterization of the coatings and revealed the formation of stoichiometric composition in coatings. X-ray diffraction (XRD) studies showed that (200) and (111) plane reflections of ZrN and Cr〈sub〉2〈/sub〉N phases, correspondingly, were with maximum intensity. Transmission electron microscopy (TEM) analysis revealed that the films comprise of nanometric equiaxed grains with average sizes from 12.8 to 15.1 nm for ZrN layers and from 14.5 to 28.1 nm for CrN layers. The high-temperature heat treatment caused exothermic and endothermic reactions, which were mainly attributed to the improvements or disordering of the coatings' structure, consequently. The highest values of microhardness (4966HV0.025) and nanohardness (24.58 GPa) were obtained for the sample with a bilayer thickness of 732 nm, the average crystallite size of 13.3 nm and nitrogen content of 49 at%. Experimental results indicated that deposited composites can be effectively used in the production of industrial tools, implements for cutting etc.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Manisha Kumari, Shrabani Mondal, Prashant K. Sharma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The drug loading and release properties of Eu〈sup〉3+〈/sup〉 doped GdPO〈sub〉4〈/sub〉 nanoparticles (NPs) were studied using a simple electrochemical protocol in an 〈em〉in-vitro〈/em〉 environment, taking acetaminophen as a model drug. The electrochemical monitoring of drug release was also validated with absorption spectroscopy technique. For this purpose, dual stimuli (pH and temperature) responsive monoclinic mesoporous GdPO〈sub〉4〈/sub〉 nanoparticles of size ∼22 nm were synthesized by a simple hydrothermal method. Crystal structure, size, shape, morphology, porosity, optical property and magnetic properties of the obtained product were studied by different characterization techniques. Successful loading of drug in NPs was investigated by Fourier transform infrared spectroscopy (FT-IR). Photoluminescence (PL) measurement shows orange-red color emission corresponding to 〈sup〉5〈/sup〉D〈sub〉0〈/sub〉→〈sup〉7〈/sup〉F〈sub〉2〈/sub〉 transitions of Eu〈sup〉3+〈/sup〉 ions. The vibrating sample magnetometer (VSM) measurements showed negligible hysteresis in both samples, suggesting retention of the superparamagnetic behavior of GdPO〈sub〉4〈/sub〉 NPs. The high loading capacity of 79% and encapsulation efficiency of 83% is observed when acetaminophen, an anti-fever drug, was loaded on these mesoporous GdPO〈sub〉4〈/sub〉 NPs. The drug was attached on NPs surfaces via absorption, without any special surface modification. During drug release studies, a spontaneous and smooth release from these mesoporous NPs was observed at a moderate-high temperature (37 °C) and low pH (pH 5) with no sign of burst release. These nanoparticles were capable of targeting and specific release of the loaded drug in response to pH and temperature and hence may serve as a potential drug carrier for 〈em〉in-vivo〈/em〉 applications.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339604-fx1.jpg" width="275" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Shixiang Zuo, Zhan Liu, Wenjie Liu, Xiazhang Li, Zhongyu Li, Chao Yao, Qun Chen, Yongsheng Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oriented rutile TiO〈sub〉2〈/sub〉 nanorod arrays (TiO〈sub〉2〈/sub〉 NRA) were elaborately grown on the conductive mica (C-mica) with Sb-SnO〈sub〉2〈/sub〉 seed crystal by a hydrothermal strategy to achieve TiO〈sub〉2〈/sub〉 NRA/C-mica composites. The as-obtained samples were characterized by X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and photo-electrochemical measurements. Compared with TiO〈sub〉2〈/sub〉 NP/mica, TiO〈sub〉2〈/sub〉 NRA/C-mica coated film exhibits more excellent physical barrier ability in the dark, and an enhanced photo-induced current density as well as a more negative photo-potential shift in the light, indicating remarkable photo-cathodic protection for 304 stainless steel (304SS). The distinctive 1D-2D architecture of TiO〈sub〉2〈/sub〉 NRA/C-mica facilitates the transmission and separation of photo-induced electron-hole pairs. Furthermore, it's the first time that the TiO〈sub〉2〈/sub〉 NRA/C-mica hybrid film is found to possess continuous and stable cathodic protection for the 304SS over a long period in the dark.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881834009X-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Baochen Wang, Ziyao Wang, Yangai Liu, Tao Yang, Zhaohui Huang, Minghao Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crystal structure tailoring is a commonly used method for tuning the luminescence of phosphors. This study mainly aims at luminescent spectra tuning of Sr〈sub〉1−〈em〉x〈/em〉〈/sub〉Ba〈sub〉〈em〉x〈/em〉〈/sub〉Al〈sub〉2〈/sub〉Si〈sub〉2〈/sub〉O〈sub〉8〈/sub〉:Eu〈sup〉2+〈/sup〉 phosphors by substitution of Ba for Sr ions. The phase composition was characterized by X-ray powder diffraction and the crystal structure was determined by using the Rietveld refinement method. The excitation and emission spectra, diffuse reflectance spectra, and thermal quenching were also investigated in detail. The results show that Sr〈sub〉1−〈em〉x〈/em〉〈/sub〉Ba〈sub〉〈em〉x〈/em〉〈/sub〉Al〈sub〉2〈/sub〉Si〈sub〉2〈/sub〉O〈sub〉8〈/sub〉:Eu〈sup〉2+〈/sup〉 phosphors can form a series of continuous solid solutions in the range from 0 to 0.75. With the increase in 〈em〉x〈/em〉 value, the emission spectra show an obvious redshift from 415 to 450 nm. The emission redshift plays an important role in enabling Sr〈sub〉1−〈em〉x〈/em〉〈/sub〉Ba〈sub〉〈em〉x〈/em〉〈/sub〉Al〈sub〉2〈/sub〉Si〈sub〉2〈/sub〉O〈sub〉8〈/sub〉:Eu〈sup〉2+〈/sup〉 to be used as a standard blue phosphor for application in white-light-emitting diodes.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818340465-fx1.jpg" width="303" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Jia Sun, Qian-Gang Fu, Tao Li, Guang-Peng Zhang, Rui-Mei Yuan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Constituent phases, porosity and residual stress are significant factors influencing the performance of two-dimension (2D) structural components. In present study, these factors with respect to thermally sprayed MoSi〈sub〉2〈/sub〉 based composite were elaborately adjusted through plasma spraying power to investigate the oxidation behavior in medium temperature range of 400–900 °C. By increasing the operation powers, the improved melting degree of feedstock led to the increased metastable phases and the decreased porosity in the MoSi〈sub〉2〈/sub〉 based composite but it did not remarkably affect the residual stress distribution. After the analysis on the medium-temperature oxidation, it can be concluded that the metastable phases and the porosity were principally responsible for the enhanced oxidation resistance of the MoSi〈sub〉2〈/sub〉 based composite. The thermal-sprayed 2D MoSi〈sub〉2〈/sub〉 based composites with large amounts of 〈em〉β〈/em〉 phases and low porosity can achieve the outstanding oxidation resistance in medium temperature range.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Li Jin, Jun Qiao, Lei Hou, Liang Wang, Lin Zhang, Xu Lu, Hongliang Du, Xiaoyong Wei, Yan Yan, Gang Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Perovskite ferroelectric ceramics with 〈em〉T〈/em〉〈sub〉〈em〉m〈/em〉〈/sub〉 (temperature corresponding to maximum dielectric permittivity 〈em〉ε〈/em〉′) around room temperature and high electrostrictive coefficient 〈em〉Q〈/em〉〈sub〉33〈/sub〉 are of interest to the applications in high-precision actuators, since low-hysteresis/non-hysteresis and high strain response can be generated in these materials based on a purely electrostrictive effect. In this work, undoped Ba(Zr〈sub〉0.2〈/sub〉Ti〈sub〉0.8〈/sub〉)O〈sub〉3〈/sub〉 (BZT) and La〈sup〉3+〈/sup〉-doped Ba(Zr〈sub〉0.2〈/sub〉Ti〈sub〉0.8〈/sub〉)O〈sub〉3〈/sub〉 (BLZT) lead-free ferroelectrics were synthesized by solid state reaction method. Their dielectric and ferroelectric properties were investigated systematically with an emphasis on electrostrictive effect. With respect to increase of La〈sup〉3+〈/sup〉 content from 0 to 1%, the 〈em〉T〈/em〉〈sub〉〈em〉m〈/em〉〈/sub〉 of BLZT decreases from 44.5 °C to 14.6 °C, and the diffuseness degree 〈em〉γ〈/em〉 increases from 1.814 to 1.993. A conductive mechanism, which is prominent in undoped BZT, is inhibited drastically by introducing the La〈sup〉3+〈/sup〉 into BZT. A high electrostrictive strain of 0.08% and a low hysteresis 〈em〉η〈/em〉 (〈10%) are obtained simultaneously in 〈em〉x〈/em〉 = 0.25% composition at room temperature. The 〈em〉Q〈/em〉〈sub〉33〈/sub〉 ranges from 0.0377 m〈sup〉4〈/sup〉/C〈sup〉2〈/sup〉 and 0.0537 m〈sup〉4〈/sup〉/C〈sup〉2〈/sup〉. This work not only reports a high electrostrictive effect in BLZT ferroelectrics, but also provides BLZT ceramics with a potential application in high-precision actuators.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Fuwen Yu, Chunjin Hang, Menghui Zhao, Hongtao Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A die-attach material based on an Sn-coated Ni core-shell powder with a high re-melting temperature can be used for high-temperature applications. The outer Sn layers of the Sn-coated Ni particles possess a low melting point of 232 °C and can be completely converted into a Ni〈sub〉3〈/sub〉Sn〈sub〉4〈/sub〉 intermetallic compound with a high re-melting point of 794.5 °C after reflowing at a low temperature of 250 °C for 40 min. This die-attach material exhibits an excellent high-temperature operational capability, with a high shear strength of 40.2 MPa at 500 °C. The coefficient of thermal expansion (CTE) of the reflowed preform is between those of SiC and Cu, which is highly beneficial for mitigating the stress caused by the CTE mismatch between these materials. In addition, the thermal conductivity of the bondline is sufficiently high for heat dissipation during operation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): José C.S. Filho, Sérgio C. Zilio, Djalmir N. Messias, Viviane Pilla, Anielle C.A. Silva, Noelio O. Dantas, Acácio A. Andrade〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The thermal expansion (〈em〉α〈/em〉) and the thermo-optic (d〈em〉n〈/em〉/dT) coefficients of a phosphate glass dubbed as PANK were simultaneously measured using a single arm double interferometer from 100 to 400 K of the temperature range. An athermal behavior of the optical path difference in a two-beam interferometer was found around 200 K. This result is in agreement with a similar observation carried out applying the Thermal Lens spectrometry (TLS) of Nd-doped PANK glass at ∼180 K. The main difference between these temperature values is ascribed to the sample surface curvature induced by the laser beam in thermal lens measurements. The athermal behavior shows that this glass has the potential for laser applications as an ion host at low temperature, and small changes in the glass composition should be explored to bring this property to room temperature.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339306-fx1.jpg" width="288" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): B.N. Sahoo, S.K. Panigrahi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magnesium matrix in-situ composites with hybrid TiC+TiB〈sub〉2〈/sub〉 reinforcement are potential materials for automobile and aerospace applications. It is essential to establish the processing map of such composites as these materials may undergo several thermo-mechanical processes while manufacturing engineering components. In the current work, AZ91 Magnesium matrix TiC+TiB〈sub〉2〈/sub〉 reinforces hybrid in-situ along with its base counterpart were developed and subjected to solutionization followed by peak aging treatment. The safe processing zone for both base and in-situ composite at all heat treatment conditions have been established through processing map based on dynamic materials model (DMM) by conducting hot compression tests at various temperatures (250 °C – 450 °C) and strain rates (0.001 s〈sup〉−1〈/sup〉 – 10 s〈sup〉−1〈/sup〉). Two regions: stable and instable were identified from processing map for all the material conditions. Dynamic recrystallization is the main dominant mechanism in stable region, whereas instable region is characterized by twin and intergranular cracks. To understand the mechanism of hot deformation behavior, activation energy is calculated based on constitutive model for all material conditions. The developed in-situ composite in peak aged condition is found to possess higher activation energy (∼230 kJ/mol) as compared to base alloy (∼126 kJ/mol). A correlation between constitutive model and processing map have been established with an emphasis on their microstructures.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339483-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Chuanjun Li, Rui Guo, Shengya He, Weidong Xuan, Xi Li, Yunbo Zhong, Zhongming Ren〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The formation of the microstructures in the hypo- and hypereutectic Al〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Cu alloys in the steady magnetic field (SMF) was investigated using the conventional quenching technique. In comparison with quenched structures without the SMF, the additional bulky phases, i.e. θ-Al〈sub〉2〈/sub〉Cu phase and the supersaturated α solid solution, were found to form in the Al-26 wt%Cu and Al-45 wt%Cu alloys quenched in the SMF, respectively. The temperature measurements showed that the maximum cooling rate of the quenched sample in the SMF was markedly higher than that without the SMF and thus a larger undercooling was obtained in the SMF. The microstructure formation in the SMF can be rationalized using the Al〈img src="https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Al〈sub〉2〈/sub〉Cu phase diagram with metastable extensions and the coupled growth zone.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Wenmin Guo, Bin Liu, Yong Liu, Tianchen Li, Ao Fu, Qihong Fang, Yan Nie〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Refractory high-entropy alloys (RHEAs) are promising high-temperature structural materials due to their high melting point and extraordinarily high yield strength. However, their industrial application is greatly restricted due to their limited room-temperature ductility. In the present investigation, a ductile and strong single-phase NbTaTiV RHEA was synthesized by powder metallurgy method. Effects of the sintering temperature on the phase formation, microstructural evolution and the mechanical properties of the NbTaTiV RHEA were characterized. The results show that the NbTaTiV RHEA sintered at 1700 °C has an equiaxed single bcc phase microstructure, no obvious porosity and compositional segregation can be observed. The alloy exhibits a relatively high hardness of 510 HV, yield strength of 1.37 GPa, and compressive fracture strength of 2.19 GPa with a high fracture strain of 23% at room temperature. Typical strain softening and steady state flow occur during compressive deformation at high temperatures. During deformation at 1000 °C, the alloy still exhibits high yield strength of 437 MPa with a compression strain over than 40%. The outstanding mechanical properties is mainly attributed to the homogeneous and fine microstructures, and solid solution strengthening effect. It can be concluded that the powder metallurgy is a promising way for preparing ductile RHEAs with outstanding comprehensive mechanical properties.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Thiquynhxuan Le, Qi Wang, A.V. Ravindra, Xiteng Li, Shaohua Ju〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel microwave heating process for the synthesis of zeolite-Y from spent fluid catalytic cracking (SFCC) catalyst has been proposed in this work. The SFCC catalyst is firstly activated in microwave field by acid solution and then used as an aluminum source for the synthesis of zeolite-Y. The activation effect of hydrochloric acid and oxalic acid on the SFCC catalyst, and the synthesis effects of zeolite-Y production from the activated SFCC catalyst under microwave are studied by ICP, XRD, SEM, and N〈sub〉2〈/sub〉 sorption studies. The results show that microwave-assisted acid activation process can facilitate the formation of the active γ-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and as well enhance the crystallinity of zeolite-Y in the SFCC catalyst, which is beneficial for the synthesis of zeolite-Y. Compared with the inactivated SFCC catalyst, the activated SFCC catalyst has a larger specific surface area and a lower contaminated metal content. The specific surface areas of SFCC catalyst after activation by hydrochloric acid and oxalic acid are 197.1 and 113.6 m〈sup〉2〈/sup〉/g, respectively, indicating better activation by hydrochloric acid compared to oxalic acid in the microwave field. The results demonstrate that increasing the synthesis temperature and prolonging the crystallization time favor the growth of zeolite-Y crystal particles, however, zeolite-Y partially transforms into zeolite-P. The priority of different aluminum sources in zeolite-Y synthesis is: hydrochloric acid activated SFCC catalyst 〉 oxalic acid activated SFCC catalyst 〉 inactivated SFCC catalyst. The zeolite-Y having a particle size range of 0.3–1 μm is successfully synthesized from the activated SFCC catalyst at 100 °C for 2 h under microwave at 2 kg/cm〈sup〉2〈/sup〉 pressure and 1000 W power.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Qing Zhou, Yin Du, Yue Ren, Wangwang Kuang, Weichao Han, Haifeng Wang, Ping Huang, Fei Wang, Jian Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Friction and wear are the two most important properties that determine the long-term performances of metallic glasses as much as strength and ductility. With this in mind, a multilayered strategy was proposed to improve the nano-scratching properties of metallic glass thin films and the well-characterized Zr-based metallic glasses were chosen to be the representative model materials in current work. It was found that the metallic glass could exhibit improved wear resistance and reduced friction coefficient if it is made in the form of multilayers. The complexity in the temporal scale of the lateral force signal is investigated, elucidating the inhomogeneous (and homogeneous) shear-banding processes during the nanoscratching process. The statistical and dynamic analyses of the stick-slip behaviors showed a transition from a chaotic to a self-organized critical state in the multilayers, indicating that the hetero-interfaces promote extensive shear band-interface interactions and induce the scratch hardening effect, both of which are responsible to the excellent tribological properties. The current work not only highlights the significant roles of hetero-interfaces in improving the nano-tribological properties but also make the multilayered metallic glass thin films a promising candidate towards structural and functional applications for metallic glasses.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339446-fx1.jpg" width="280" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): P. Sochacka, A. Miklaszewski, M. Jurczyk〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Titanium-based alloys with fine grain structure represent a class of engineering materials that can exhibit a unique combination of properties. This paper presents the structural evolution of the β phase in Ti-x at. % Mo (x = 10, 23, 27, 31 and 35) alloys synthesized by mechanical alloying with different milling times between 15 min and 48 h and powder metallurgical process with cold powder compaction and sintering or interchangeably hot pressing. The binary alloys were characterized by X-ray diffraction, scanning electron microscopy, chemical composition determination as well as density and porosity measurements. The influence of the chemical composition and method of processing on the final microstructure, and mechanical properties of bulk alloys were studied. The mechanically alloyed Ti23Mo, Ti27Mo and Ti31Mo materials upon sintering at 800 °C for 5 min led to the formation of single β type phase alloys. All these β-type alloys have elastic modulus lower than CP microcrystalline α-Ti, but their hardness is nearly 3 times higher (approx: 460 HV〈sub〉0.3〈/sub〉). The present study has demonstrated that these single phase β-type alloys with fine grain microstructure can be fabricated by the application of hot pressing of mechanically alloyed powders at the temperature below α→β transus (800 °C).〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881833891X-fx1.jpg" width="145" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Li Wan, Yun-Lai Deng, Ling-Ying Ye, Yong Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The natural ageing effect on artificial ageing kinetics of Al-Zn-Mg alloy has been studied using small angle X-ray scattering, transmission electron microscopy and mechanical testing methods. The results have demonstrated that with 72 hours natural ageing treatment prior to pre-ageing process can inhibit following natural ageing effect. Samples with direct pre-ageing treatment after quenching from solution temperature exhibit significant natural ageing effect subsequently. The strengthening effect is mainly attributed to the formation of fine GP-zones with particle sizes of less than 1 nm. The microstructures characterization has shown that these GP-zones may transform to precursor of η′ precipitate during pre-ageing process if their size reached a critical size. These precursor of η′ precipitate with the size of ∼1 nm–∼1.2 nm are stable at room temperature.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): A. Brzoza, M. Kowalczyk, A. Wierzbicka-Miernik, P. Czaja, W. Maziarz, A. Wójcik, J. Wojewoda-Budka, M. Sikora, J. Dutkiewicz, M.J. Szczerba〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ni-Mn-Ga-Co-Cu melt spun ribbons were investigated in the as-cast and annealed states. The initial microstructure of the ribbons was highly anisotropic along the growing direction and was characterized by three different regions of equiaxed, columnar and dendritic grains. At ambient temperature, the microstructure was composed of two martensitic phases, i.e. non-modulated and seven-layer modulated, and the high temperature L2〈sub〉1〈/sub〉 austenite phase. The stabilization of the austenite phase was a consequence of a strong grain size reduction, especially close to the “contact” side of the ribbons. Subsequent annealing at 823 K triggered atomic ordering, which promoted an improvement in the magnetization. Additional annealing at 1173 K brought about a substantial refinement of the microstructure. The ribbon structure changed to a single non-modulated martensite phase, whereas on a microstructural level, the grains and martensitic plates coarsened considerably. The annealed ribbons resembled oligo-crystalline materials and may cause interest for magnetic field-induced strain applications.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339057-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Priyanka Nehla, Clemens Ulrich, Rajendra S. Dhaka〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report the structural, transport, electronic, and magnetic properties of Co〈sub〉2〈/sub〉FeGa Heusler alloy nanoparticles. The Rietveld refinements of x-ray diffraction (XRD) data with the space group Fm〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉3〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉m clearly demonstrates that the nanoparticles are of single phase. The particle size (D) decreases with increasing the SiO〈sub〉2〈/sub〉 concentration. The Bragg peak positions and the inter-planer spacing extracted from high-resolution transmission electron microscopy image and selected area electron diffraction are in well agreement with data obtained from XRD. The coercivity initially increases from 127 Oe to 208 Oe between D = 8.5 nm and 12.5 nm, following the D〈sup〉−3/2〈/sup〉 dependence and then decreases with further increasing D up to 21.5 nm with a D〈sup〉−1〈/sup〉 dependence, indicating the transition from single domain to multidomain regime. The effective magnetic anisotropic constant behaves similarly as coercivity, which confirms this transition. A complex scattering mechanisms have been fitted to explain the electronic transport properties of these nanoparticles. In addition we have studied core-level and valence band spectra using photoemission spectroscopy, which confirm the hybridization between 〈em〉d〈/em〉 states of Co/Fe. Further nanoparticle samples synthesized by co-precipitation method show higher saturation magnetization. The presence of Raman active modes can be associated with the high chemical ordering, which motivates for detailed temperature dependent structural investigation using synchrotron radiation and neutron sources.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Xin Zhang, Ming Zhang, Tianyu Cui, Jinman Li, Qingsuo Liu, Haibo Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The microstructure and the shape memory effect of Cu-13.0Al-4.0Ni high temperature shape memory alloys doped with different contents of boron (0.25 wt%, 0.5 wt%, 1.0 wt%, and 2.0 wt%) were studied in this paper. According to the obtained results, it was observed that the microstructure and the shape memory effect were sensitive to the addition of boron, and the addition of boron not only enhanced the mechanical properties of the Cu-13.0Al-4.0Ni alloy, but also greatly improved the shape memory effect of the alloy. The fracture of martensite changed from intergranular fracture to transgranular cleavage fracture. In addition, it was found that the highest shape memory effect was achieved by the addition of 0.25 wt% boron.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Sen Gao, Xian Zhang, Qingfeng Zeng, Shiyu Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crystalline 〈em〉α〈/em〉-TeO〈sub〉2〈/sub〉 was investigated at ambient pressure using 〈em〉ab initio〈/em〉 calculations. The effect of pressure on 〈em〉α〈/em〉-TeO〈sub〉2〈/sub〉 was studied from 0 to 10 GPa. The lattice parameters and elastic constants calculated by LDA and GGA method at 0 GPa both agree with the available theoretical and experiment results. The elastic constants 〈em〉C〈/em〉〈sub〉〈em〉ij〈/em〉〈/sub〉, the bulk modulus 〈em〉B〈/em〉, the shear modulus 〈em〉G〈/em〉, Young's modulus 〈em〉E〈/em〉, and the ductile and brittle character (〈em〉B〈/em〉/〈em〉G〈/em〉) were calculated and examined in detail. It was found that the calculated universal anisotropy index indicated that 〈em〉α〈/em〉-TeO〈sub〉2〈/sub〉 has anisotropy under 0 GPa, and with the pressure increases, its elastic anisotropy increases. Furthermore, from the mechanical stability criteria, it is show that the structure of tetragonal 〈em〉α〈/em〉-TeO〈sub〉2〈/sub〉 is not stable above 5.1 GPa. Finally, the electronic and optical properties were also investigated, and the results show that, on increasing the external pressure, the energy bandgap increases, with the optical spectrum exhibiting anisotropy in the 〈em〉x〈/em〉 and 〈em〉z〈/em〉 directions and a small blue shift under pressure.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Jens Reiser, Andreas Hoffmann, Johannes Hain, Ute Jäntsch, Michael Klimenkov, Jörg Hohe, Tobias Mrotzek〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉This paper describes a systematic analysis of liquid-phase infiltrated molybdenum (Mo) copper (Cu) composites, deformed by various levels, and elucidates the impact of (i) the copper content, and (ii) the rolling reduction on the evolution of the material properties. The rolling-induced change of the thermo-physical properties can be traced back to (ii-a) the evolution of the geometry (viz. the flattening of the molybdenum and the copper phase during rolling) and (ii-b) the evolution of the crystallographic texture.〈/p〉 〈p〉Four infiltrated ingots with a copper content of 23, 39, 48 and 54 vol % were produced. Each ingot was gradually rolled down to a final degree of deformation of 0.5, 1, 1.5, 2 and 2.38, which corresponds to a rolling reduction of 39%, 63%, 78%, 86% and 90%. In summary, four material compositions (23, 39, 48 and 54 vol % Cu) in six conditions (as-infiltrated and five as-rolled conditions) were examined.〈/p〉 〈p〉The evolution of the microstructure is correlated with the evolution of the mechanical and thermo-physical properties such as hardness (HV2), Young's modulus, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉E〈/mi〉〈/mrow〉〈/math〉, electrical conductivity, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mi〉σ〈/mi〉〈/mrow〉〈/math〉, thermal conductivity, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si3.gif" overflow="scroll"〉〈mrow〉〈mi〉k〈/mi〉〈/mrow〉〈/math〉, and the coefficient of thermal expansion, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.gif" overflow="scroll"〉〈mrow〉〈mi〉α〈/mi〉〈/mrow〉〈/math〉 (CTE, in the range of 350 °C (623 K) – 750 °C (1023 K)).〈/p〉 〈p〉It was found, that the same thermal conductivity can be gained by using either a low copper-content composite that features a low degree of deformation or by using a high copper-content composite that was rolled down to a high degree of deformation.〈/p〉 〈p〉Furthermore, we were able to demonstrate that peculiarities in the CTE-over-T curves can be traced back to the plastic deformation of the copper phase, which is affected by rolling-induced residual stresses and recrystallisation processes during the CTE measurement.〈/p〉 〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339094-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 775〈/p〉 〈p〉Author(s): Feng Hong, Haiming Cheng, Yan Song, Dan Li, Guixia Liu, Wensheng Yu, Jinxian Wang, Xiangting Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Non-rare-earth red phosphors as alternative to commercial (oxy) nitride phosphors have attracted considerable attention for energy-efficient warm white light-emitting diodes (WLEDs). An excellent narrow-band red emission K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 product was successfully obtained through co-precipitation method. The crystal structure, morphology, composition and optical properties of K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 samples were investigated in details 〈em〉via〈/em〉 X-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive spectrometry (EDS) and photoluminescence spectra, respectively. Mn〈sup〉4+〈/sup〉 activated K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉 red phosphor possesses two strong and wide absorption bands in the region of 300–500 nm, which can be applied to UV and blue LED chips and bright intense red light (635 nm) with high color purity. Simultaneously, mechanisms of concentration and temperature quenching were systematically elucidated. After a systematic investigation, the luminescence properties of K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 have been optimized by changing synthetic conditions, such as the doping concentration, the concentration of HF, the potassium source, the amount of KF and the addition of surfactant. The red phosphor K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 was packaged 〈em〉via〈/em〉 mixing commercial YAG:Ce yellow phosphor, an outstanding warm WLED with low CCT (3882 K), high CRI (Ra = 90.4) and high luminous efficacy (LE) of 125.84 lm/W has been obtained, implying that K〈sub〉2〈/sub〉GeF〈sub〉6〈/sub〉:Mn〈sup〉4+〈/sup〉 is the potential red phosphor for warm WLEDs.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818331839-fx1.jpg" width="329" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Guozhong Huang, Peipei Zhang, Zhiming Bai〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A novel ZnO nanowire arrays (NAs)/graphene(G)/CdS/electrolyte heterojunction was successfully prepared via a simple three-step synthesis method when applied for photoelectrochemical type self-powered UV–visible photodetectors. Under zero bias, the responsivities of the self-powered UV–visible photodetectors on the basis of ZnO NAs/G/CdS/electrolyte heterojunctions are 27.3 mA/W and 4.3 mA/W for the UV and visible light, respectively, with fast rise and decay times (5 ms). Graphene improves the response of ZnO NAs to UV and visible light to a certain extent owing to its excellent charge-collecting ability and the acceleration of carrier separation and transference. After covering photosensitive CdS nanoparticles, the response to visible light is greatly increased because of the type II energy band structure of ZnO/CdS. It could be inferred from the evidence that the ZnO NAs/G/CdS/electrolyte heterojunction performs effectively in the aspect of self-powered UV–visible detection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): W. Cui, J. Pan, D.J. Blackwood, Y. Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Many previous simulations of the plastic deformation in metallic glasses showed that shear banding is the dominant mode accompanied by Voronoi volume continuous generation and softening. In the present work, we report a contrary phenomenon where Voronoi volume recovery is dominant during plastic deformation in CuZr metallic glasses under tension. By creating a notched geometry, the deformation mode of notched samples transits from shear banding to necking due to the introduction of triaxial stress state. With the suppressing of shear banding, a notch strengthening and structure ordering phenomenon together with the recovery of Cu-centered full-icosahedra fraction are also observed. The present work enriches our understanding on the mechanical behavior and deformation mechanism of metallic glasses.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339124-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Ting Wang, Ke Han, Qi Tang, Binggang Zhang, Jicai Feng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Electron beam welding of titanium to copper has been performed with different Cu-V filler metals. Microstructure, mechanical properties and fracture behavior were investigated. Compared with the welded joint without filler metal, the lower V content in Cu75V25 filler metal resulted in the formation of fine Ti-Cu compounds in the interface of TA15 side. Thus, the joint showed a lower tensile strength and fractured along the interfacial reactive layer. When V content is over 34 wt% in the filler metal, the interfacial microstructure near TA15 side formed cellular (Ti,V) solid solution to replace the Ti-Cu compounds, which improved the mechanical properties of the joint. As a result, the joint with Cu66V34 filler metal displayed the highest tensile strength (384 MPa), approaching 82% of that of the copper base metal (BM), and fractured in heat affected zone (HAZ) of copper side, due to the local softening by grains coarsening. In spite of the formed solid solution at the interface, the joint welded with Cu34V66 filler metal containing higher V content, produced amount of pores and unmelted V alloy, which resulted in the decrease of tensile strength down to 55% of that of the copper BM.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818338969-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): M. Bououdina, A.A. Dakhel, A. Jaafar, J.H. Dai, Y. Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉This research work aims to study the effect of co-doping by Al〈sup〉3+〈/sup〉 to increase the electronic charge carrier concentration inversely to Mg〈sup〉2+〈/sup〉. Zn〈sub〉0.97〈/sub〉Gd〈sub〉0.03〈/sub〉O, Zn〈sub〉0.95〈/sub〉Gd〈sub〉0.03〈/sub〉Mg〈sub〉0.02〈/sub〉O, and Zn〈sub〉0.95〈/sub〉Gd〈sub〉0.03〈/sub〉Al〈sub〉0.02〈/sub〉O nanopowders were synthesised by simultaneous thermal co-decomposition of a mixture of cadmium and metal complexes, followed by hydrogenation at 350 and 600 °C. This study aimed at establishing the preparation conditions including hydrogenation that were essential for the creation of room temperature ferromagnetic order starting from the paramagnetic Gd-doped ZnO by using structural and electronic consequences of codoping with ions of Al or Mg. X-ray diffraction analysis confirms total doping of (Gd, Mg and Al) impurities into ZnO host lattice as well as the absence of secondary compounds/oxides in the synthesised solid solutions. The reflectance has been found to be significantly affected upon co-doping and hydrogenation, while the energy band gap decreases slightly; i.e. Eg = 3.23–3.00 eV. Magnetic measurements reveal that all the as-synthesised doped ZnO powders gained paramagnetic behaviour defeating the diamagnetic characteristic of ZnO, due to the presence of Gd ions with an effective magnetic moment in the range 8.04–7.12 μ〈sub〉B〈/sub〉. The hydrogenation in the present work conditions did not change the paramagnetic behaviour except for ZnO:Gd:Al-H, showing a partial a magnetic order overlapping with paramagnetic component, resulting in a coercivity of 170.2 Oe, remanence of 0.550 memu/g, and saturation magnetization of 2.14 memu/g. Therefore, the conditions including hydrogenation that were necessary to create FM ordering were determined.〈/p〉 〈p〉First-principles calculations indicate that the Gd doped ZnO systems own large spin polarized effect due to the interaction between Gd-〈em〉f〈/em〉 and O-〈em〉p〈/em〉 electrons. The Mg and Al dopants can modulate the values of magnetic moments.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Jikang Sun, Wen Zhang, Shiying Wang, Yibin Ren, Qingyun Liu, Yanfang Sun, Lin Tang, Jinxue Guo, Xiao Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oxygen evolution is the vital and limiting reaction in electrochemical water splitting because of the sluggish kinetics and searching efficient nonprecious metal electrocatalysts is a crucial demand to obtain sustainable and clean fuels. Transition metal borides have recently attracted increasing attention as promising catalysts for oxygen evolution reaction. Herein, ultrathin Ni-Co-B nanosheets have been vertically aligned on reduced graphene oxide as exceptionally efficient oxygen evolution reaction electrocatalyst for the first time. Controlled experiments indicate the critical role of reduced graphene oxide in guiding the formation of Ni-Co-B nanosheet. The catalyst affords a current density of 10 mA cm〈sup〉−2〈/sup〉 at low overpotential of 280 mV, which is better than most of metal boride catalysts reported to date. Stable current output is maintained at 20 mA cm〈sup〉−2〈/sup〉 for at least 60 h. We expect this work will arouse the interests on design of compositing two-dimensional metal borides with graphene, C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, and metal dichalcogenides towards applications in energy storage and conversion, electrocatalysis, and sensing.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881833977X-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Mikio Fukuhara, Tomoyuki Kuroda, Fumihiko Hasegawa, Yasuyuki Shirai, Toshiyuki Hashida, Kazuya Konno〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Blackish amorphous aluminium oxide film on AlY〈sub〉10〈/sub〉 amorphous alloy ribbons was prepared by anodic polarization process in H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 solutions, showing electric storage on uneven surfaces with a convexity of 18 nm in diameter. The longest discharging time was obtained by current ratio (I〈sub〉2〈/sub〉/I〈sub〉1〈/sub〉) of 0.4 at 16 V and 5 mass% H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉. The discharging time increases and decreases with increasing charging time and charging current, and then saturates after around 100 s and 1 μA, respectively. The resulting film shows a vertical line after Warburg region in a Nyquist diagram, rapid increases in the imaginary impedance, and a phase angle of −90° at 1 mHz in the Bode diagram, demonstrating evidence for use in an electric distributed constant circuit. The film indicates a switching effect for both positive (∼+8.6 eV) and negative (∼-11.2 eV) potentials.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Ping Zhou, Tianli Han, Cuiping Gu, Jinjin Li, Zihan Shen, Huigang Zhang, Junjie Niu, Jinhuai Liu, Jinyun Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉High energy density Li-S battery has attracted broad attention; however the capacity retention is still non-ideal. The major challenge is to find a way to effectively prevent the shuttle effect of the lithium polysulfides during charging/discharging. Here, we present a novel wheel-confined composite consisting of MnO〈sub〉2〈/sub〉 nano-rod as wedge and SnO〈sub〉2〈/sub〉 sphere as the skeleton filled with sulfur, which was synthesized using a facile chemical method. The battery with the S@MnO〈sub〉2〈/sub〉@SnO〈sub〉2〈/sub〉 composite as cathode exhibits a capacity as high as 1323 mAh g〈sup〉−1〈/sup〉 at 0.1 C and a high capacity retention of only 0.03% decay per cycle over 500 cycles, which indicates a greatly reduced shuttle effect in Li-S batteries. The battery also shows good rate-performance and low-temperature properties. In addition, the I-V measurements and the first-principle calculations have demonstrated an enhanced electron transfer through the composite.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818338465-fx1.jpg" width="279" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Shiqiang Yue, Hua Zhang, Rijin Cheng, Anding Wang, Yaqiang Dong, Aina He, Hongwei Ni, Chain-Tsuan Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Magnetic and thermal stabilities of Fe-based amorphous alloys with high saturation flux density (〈em〉B〈/em〉〈sub〉s〈/sub〉) are important for the application and understanding of the atomic interaction. Fe〈sub〉〈em〉x〈/em〉〈/sub〉(Si〈sub〉3〈/sub〉B〈sub〉13〈/sub〉)〈sub〉(100-x)/16〈/sub〉 (〈em〉x〈/em〉 = 86-71) eutectic amorphous alloys with superior manufacturability and Fe content limit were developed and the compositional effects were investigated. The alloys exhibit high 〈em〉B〈/em〉〈sub〉s〈/sub〉 of 1.53–1.68 T, low coercivity of 2.2–4.3 A/m, and high permeability of 8.8–12.8 × 10〈sup〉3〈/sup〉. With the increase of Fe content, it is found that the 〈em〉B〈/em〉〈sub〉s〈/sub〉 have an inflection point, the crystallization and Curie temperatures decrease drastically. The high Fe content alloys exhibit reduced thermal stabilities of magnetic properties, because the enhanced magnetic intercoupling effect is much lower than the weakened atomic bonding. For the alloys with 〈em〉x〈/em〉 = 71–74, the decline rate of 〈em〉B〈/em〉〈sub〉s〈/sub〉 is still lower than 10% at the extreme condition of 200 °C, while 〈em〉B〈/em〉〈sub〉s〈/sub〉 of the alloy with 〈em〉x〈/em〉 = 84 decreases more than 10% at 120 °C. The thermal stability of magnetic properties should be taken into consideration for the devices used in unique condition, especially for the high 〈em〉B〈/em〉〈sub〉s〈/sub〉 amorphous alloys.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Milivoj Plodinec, Ivana Grčić, Marc G. Willinger, Adnan Hammud, Xing Huang, Ivana Panžić, Andreja Gajović〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Novel forms of black TiO〈sub〉2〈/sub〉 nanotubes-based photocatalysts for water purification were prepared. Two features were combined: decoration of TiO〈sub〉2〈/sub〉 nanotube arrays with Ag nanoparticles (sample TiO〈sub〉2〈/sub〉-NT's@Ag) and further hydrogenation of this material (TiO〈sub〉2〈/sub〉-NT's@Ag-HA). Obtained photocatalysts show high efficiency for degradation of salicylic acid, a typical water-borne pollutant. The photocatalysts considerably exceed the photocatalytic properties of TiO〈sub〉2〈/sub〉 nanotubes and commercial TiO〈sub〉2〈/sub〉 P25 taken as a reference for modeling of the photocatalytic process. The comparison of photocatalytic activities between novel photocatalyst was based on a numerical approach supported by the complex kinetic model. This model allowed a separate study of different contributions on overall degradation rate. The contributions include: salicylic acid photolysis, photocatalysis in UVB, UVA and in the visible part of applied simulated solar irradiation. The superior photocatalytic performance of the photocatalyst TiO〈sub〉2〈/sub〉-NT's@Ag-HA, particularly under visible irradiation, was explained by the combined effect of a local surface plasmon resonance (LSPR) due to Ag nanoparticles and creation of additional energy levels in band-gap of TiO〈sub〉2〈/sub〉 due to Ti〈sup〉3+〈/sup〉 states at nanotube surfaces. The presence of Ag also positively influence charge separation of created electron-holes pairs. The synergy of several effects was quantified by a complex kinetic model through the factor of synergy, 〈em〉f〈/em〉〈sub〉Syn〈/sub〉. Stability testing indicated that the catalysts were stable for at least 20 h. The novel design of catalysts, attached on Ti foils, presents a solid base for the development of more efficient photocatalytic reactors for large-scale with a long-term activity.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339197-fx1.jpg" width="381" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Jian Wang, Yangyang Yin, Hongxia Jin, Jianwen Zhang, Yan Li, Chengwei Wang, Moyi Duan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The composite structures of tightly embedding the rare-earth oxide La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles into TiO〈sub〉2〈/sub〉 film are designed and have been successfully prepared by using the sol-gel and spin-coating method. Appearance of a large amount of nano-cracks on the La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@TiO〈sub〉2〈/sub〉 composite film surface supplies a textured surface to study the effect of nanostructured surface on the electrowetting on dielectric (EWOD) performance. The characterizations of chemical composition and crystal phase structure indicate the La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 nanoparticles with polycrystalline nature have been grown and distribute uniformly in TiO〈sub〉2〈/sub〉 film. Valuably, plenty of intimate contact heterogeneous La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/TiO〈sub〉2〈/sub〉 interfaces are formed, and supply an ideal space for charge accumulation and electric energy storage. All data of EWOD response test show the applied superlow voltage can induce a large contact angle (CA) change, but the breakdown voltage is still high. The EWOD response does not agree with the well-known Young-Lippmann equation, especially obvious in low voltage range. Moreover, the optimal parameters of layer number of 8 and La〈sup〉3+〈/sup〉 doping concentration of 0.9% are obtained to enhance EWOD response for superlow applied voltage and the lower saturation CA. Detailed investigations and analysis reveal that the electric absorption has important roles on EWOD response under superlow applied voltage for the nanostructured surface. Furtherly, the space charge polarization theory is proposed to illustrate the enhancement of EWOD performance. When the voltage is applied, plenty of charges would be accumulated on the heterogeneous La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/TiO〈sub〉2〈/sub〉 interfaces and the space charge polarization is formed, this significantly heightens polarizability of the La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉@TiO〈sub〉2〈/sub〉 composite film, and further increases their effective dielectric constant and improves EWOD performance. But the electric absorption of water on the nanostructured surface causes the inconsistency of EWOD response with the tested and calculated capacitance. The present study shows a new insight to design and fabricate structured dielectric for the solution of EWOD difficulties.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Federico J. Pomiro, Juan P. Gaviría, Gastón G. Fouga, Leonardo D. Vega, Ana E. Bohé〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The reactions of Pr〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 and Pr〈sub〉6〈/sub〉O〈sub〉11〈/sub〉 with Cl〈sub〉2〈/sub〉(g) were studied thermodynamically and experimentally, and proposed in the systems Pr〈sub〉2〈/sub〉O〈sub〉3〈/sub〉/Cl〈sub〉2〈/sub〉(g) and Pr〈sub〉6〈/sub〉O〈sub〉11〈/sub〉/Cl〈sub〉2〈/sub〉(g). A kinetic analysis was performed on Pr〈sub〉6〈/sub〉O〈sub〉11〈/sub〉 chlorination, which differs from with other light rare earth oxide chlorinations. The praseodymium oxychlorides obtained by full chlorination of Pr〈sub〉6〈/sub〉O〈sub〉11〈/sub〉 at 425 °C and 800 °C are different, being well characterized by X-ray diffraction, scanning electron microscopy, magnetic susceptibility measurements and X-ray photoelectron spectroscopy. The crystal structures of the oxychlorides were refined with the Rietveld method. The comparison between the theoretical magnetic moment of Pr〈sup〉3+〈/sup〉 and the estimated magnetic moment in the praseodymium oxychloride obtained at 425 °C revealed the presence of Pr〈sup〉3+〈/sup〉 and Pr〈sup〉4+〈/sup〉, whereas no significant difference was observed between the theoretical and the experimental values of Pr〈sup〉3+〈/sup〉 obtained for the praseodymium oxychloride prepared at 800 °C. These observations are consistent with the analyses in the X-ray photoelectron spectra for both oxychlorides. Finally, a general formula of PrO〈sub〉1+x〈/sub〉Cl is proposed for the oxychlorides synthesized at T 〈 800 °C.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Guang Chen, Jun Wang, Hongyuan Fan, Danqi Wang, Xiaoying Li, Hanshan Dong〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Possibility of improving the resistance of AISI H13 steel to molten aluminum corrosion by liquid nitrocarburizing (LNC) was explored. The effects of the LNC parameters in terms of temperatures (703/723/743 K) and soaking time (4/8/12 h) on phase transformation, microstructure, and resistance to molten aluminum were fully studied. The surface phase compositions and the cross-sectional phase distribution of the LNC treated specimens were studied by implementable X-ray diffraction analysis. Microstructure, element distribution, microhardness, and the kinetics of the nitrocarburized case formation were fully researched. Immersion test of corrosion resistance to molten aluminum was carried out at 1023 K for 30min. It is observed that an oxide layer can be produced on the top of the nitrocarburized case during LNC treatment, which cannot be regularly produced by other nitriding methods. The nitrocarburized case consists of a compound layer, a diffusion layer, and a transition layer. The growth of the nitrocarburized case is proportional to the squared treatment time and follows the Arrhenius law for the treatment temperature. The activation energy is estimated to be 195.4 kJ mol〈sup〉−1〈/sup〉. While the nitrocarburized case provided limited resistance to molten aluminum, the oxide layer formed on the top of the nitrocarburized case conferred significantly improved molten aluminum corrosion resistance, especially a duplex oxide layer produced at 743 K.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Z. Mroczek, A. Morawski, T. Czujko, F. Karaboğa, M. Akdoğan, A.J. Zaleski, M. Małecka, T. Cetner, H. Yetiş, D. Gajda, I. Belenli〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this article, the significant impact of a lamellar (layered) structure and a high isostatic pressure on the normal state resistance (〈em〉R〈/em〉〈sub〉n〈/sub〉), critical temperature (〈em〉T〈/em〉〈sub〉c〈/sub〉), irreversible magnetic field (〈em〉B〈/em〉〈sub〉irr〈/sub〉), upper magnetic field (〈em〉B〈/em〉〈sub〉c2〈/sub〉) and critical current densities (〈em〉J〈/em〉〈sub〉c〈/sub〉) at 4.2 K and 20 K was presented. Our research showed that annealing at temperatures in the range of 630 °C–680 °C (above the melting point of Mg) at atmospheric pressure (0.1 MPa) did not create a lamellar (layered) structure. This led to low 〈em〉T〈/em〉〈sub〉c〈/sub〉, 〈em〉J〈/em〉〈sub〉c〈/sub〉 and 〈em〉B〈/em〉〈sub〉irr〈/sub〉 and high 〈em〉R〈/em〉〈sub〉n〈/sub〉. The analysis, made by using scanning electron microscopy (SEM), showed that the annealing temperature increased up to 700 °C under a pressure of 0.1 MPa, which created a lamellar structure. This led to significant growth of 〈em〉T〈/em〉〈sub〉c〈/sub〉, 〈em〉J〈/em〉〈sub〉c〈/sub〉 and 〈em〉B〈/em〉〈sub〉irr〈/sub〉 and a slight increase of 〈em〉R〈/em〉〈sub〉n〈/sub〉. Moreover, the measurements showed that annealing at temperatures from 630 °C to 700 °C did not change the 〈em〉B〈/em〉〈sub〉c2〈/sub〉 value. In comparison to pressureless heat treatment, annealing under the high isostatic pressure of 1.1 GPa obtained a lamellar structure with layers of lower thickness and higher density. This led to significant increases in 〈em〉J〈/em〉〈sub〉c〈/sub〉 and 〈em〉B〈/em〉〈sub〉irr〈/sub〉 and a visible reduction of 〈em〉R〈/em〉〈sub〉n〈/sub〉. SEM analysis showed that the increase of isostatic pressure up to 0.3 GPa created a lamellar structure with thicker layers and lower density. This microstructure led to lower 〈em〉J〈/em〉〈sub〉c〈/sub〉 and 〈em〉B〈/em〉〈sub〉irr〈/sub〉 and significantly higher 〈em〉R〈/em〉〈sub〉n〈/sub〉. On the other hand, the SEM analysis showed that annealing under 0.8 GPa did not cause the formation of a layered structure, and as a result, it led to significant reductions in 〈em〉B〈/em〉〈sub〉irr〈/sub〉 and 〈em〉J〈/em〉〈sub〉c〈/sub〉 (4.2 K and 20 K) and higher 〈em〉R〈/em〉〈sub〉n〈/sub〉. The increase of the isostatic pressure from 0.1 MPa to 1.1 GPa did not affect 〈em〉T〈/em〉〈sub〉c〈/sub〉 (〈em〉B〈/em〉 = 0 T) and 〈em〉B〈/em〉〈sub〉c2〈/sub〉. The results indicated that the layered structure obtained a high density of pinning centers, which were particularly effective at higher magnetic fields. 〈em〉J〈/em〉〈sub〉c〈/sub〉 of 100 A/mm〈sup〉2〈/sup〉 in 8 T at 4.2 K was obtained in 〈em〉in situ〈/em〉 undoped MgB〈sub〉2〈/sub〉 wires after annealing at 700 °C for 40 min under an isostatic pressure of 1.1 GPa.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339434-fx1.jpg" width="267" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Si-Ming Zeng, Xin-Gui Tang, Qiu-Xiang Liu, Yan-Ping Jiang, Ming-Ding Li, Wen-Hua Li, Zhen-Hua Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉BaCe〈sub〉x〈/sub〉Ti〈sub〉1−x〈/sub〉O〈sub〉3〈/sub〉 (BCT) ceramics at x = 0.025, 0.05, 0.075 and 0.1 were prepared by the traditional solid state reaction route and sintered at 1540 °C for 6 h. The microstructural, dielectric, electrocaloric, and pyroelectric performances of BCT were systematically explored. Hysteresis loops were measured under various temperatures, and the electrocaloric effect (ECE) was calculated for all samples. The results showed that BaCe〈sub〉0.075〈/sub〉T〈sub〉0.925〈/sub〉O〈sub〉3〈/sub〉 had the best ECE which exhibited a large adiabatic temperature change of 0.81 K, an isothermal entropy change of 0.82 JK〈sup〉−1〈/sup〉kg〈sup〉−1〈/sup〉 and an electrocaloric strength of ∼0.28 Km/MV. Further, the pyroelectric figure of merits (FOMs) were analyzed and the results indicated that BaCe〈sub〉0.1〈/sub〉T〈sub〉0.9〈/sub〉O〈sub〉3〈/sub〉 would be a better candidate for pyroelectric devices which exhibited high pyroelectric coefficient (p) of 7.82 × 10〈sup〉−4〈/sup〉〈em〉Cm〈/em〉〈sup〉−2〈/sup〉K〈sup〉−1〈/sup〉 and FOM of high detectivity (F〈sub〉d〈/sub〉) of 10.39 μPa〈sup〉−1/2〈/sup〉. These results in this work would facilitated the development of the electrocaloric and pyroelectric performance of Ce-doped BaTiO〈sub〉3〈/sub〉 ceramics.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Baishun Li, Kai Guan, Qiang Yang, Xiaodong Niu, Dongdong Zhang, Shuhui Lv, Fanzhi Meng, Yuanding Huang, Norbert Hort, Jian Meng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Microstructures and mechanical properties of a Mg−8Gd−3Yb−1.2Zn−0.5Zr (wt%) alloy have been investigated. The dominant intermetallic phases in the as-cast sample are Mg〈sub〉5〈/sub〉RE (RE = Gd,Yb) phase, 14H-type long-period stacking ordered (LPSO) phase, and Mg〈sub〉2〈/sub〉Zn〈sub〉2〈/sub〉RE (W) phase and ordered Mg〈sub〉12〈/sub〉RE phase. Furthermore, the ordered Mg〈sub〉12〈/sub〉RE phase generally coexists with the W phase following an orientation relationship as [0〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉1]〈sub〉w〈/sub〉//[〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉2〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉30]〈sub〉Mg12RE〈/sub〉, and (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉11)〈sub〉w〈/sub〉//(001)〈sub〉Mg12RE〈/sub〉. After extrusion, the microstructure is consisted of un-recrystallized regions along with a small part of fine dynamically recrystallized (DRXed) regions. Simultaneously, the coarse Mg〈sub〉5〈/sub〉RE, W and Mg〈sub〉12〈/sub〉RE particles were disintegrated and mainly distribute at extrusion stringers while the fine LPSO plates mainly distribute in un-recrystallized regions. Moreover, amounts of nanoscale Mg〈sub〉5〈/sub〉RE particles were dynamically precipitated in DXRed regions. Then, the as-extruded Mg−8Gd−3Yb−1.2Zn−0.5Zr alloy exhibits clearly higher strength than the classic rare-earth-containing magnesium alloys with comparative or even much higher rare earth content at both room temperature and high temperatures. The dominant strengthening mechanism was finally revealed as precipitation/dispersion strengthening.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): An-Nan Chen, Meng Li, Jia-Min Wu, Li-Jin Cheng, Rong-Zhen Liu, Yu-Sheng Shi, Chen-Hui Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Highly porous mullite ceramics with bimodal pore structures were fabricated by selective laser sintering (SLS), in which the closed pores were provided by core-shell structure of fly ash hollow spheres (FAHSs) and the open pore channels were created by spherical polyamides (PA12). With increasing sintering temperature, the total porosity of mullite ceramics decreased, in which the average closed pore size reduced and the average open pore size distribution kept constant, however, the compressive strength of ceramic foams increased. This strength enhancement was mainly attributed to the reinforced sintering necks between FAHSs when sintered below 1350 °C, which resulted from the liquid phase diffusion of K, Ca and Ti, while the densification and thickening of sphere shell walls played a key role when above 1350 °C. Our findings illustrate that understanding pore structure characteristics and strength enhancement mechanism changes will be helpful for designing highly porous mullite ceramics with high mechanical performance.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818340362-fx1.jpg" width="281" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Ting Zhang, Lehua Qi, Jiawei Fu, Jiming Zhou, Xujiang Chao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In the present study, carbon fibers grafted with SiC nanowires (C〈sub〉f〈/sub〉-SiCNWs) reinforced AZ91D composite (C〈sub〉f〈/sub〉-SiCNWs/AZ91D) was prepared by liquid-solid extrusion following vacuum infiltration (LSEVI) process. The effect of SiC nanowires (SiCNWs) on the interfacial microstructure, tensile properties and fracture behavior of the C〈sub〉f〈/sub〉-SiCNWs/AZ91D composite were investigated. First, the microstructure and fracture surface of the composite were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results showed that after introducing SiCNWs, the antioxidation of carbon fiber could be reasonably improved, which provided a better interface of the C〈sub〉f〈/sub〉-SiCNWs/AZ91D composite by preventing the detrimental interfacial reaction product of Al〈sub〉4〈/sub〉C〈sub〉3〈/sub〉. Then, the average ultimate tensile strength of SiCNWs-C〈sub〉f〈/sub〉/AZ91D composite was compared with that of C〈sub〉f〈/sub〉/AZ91D composite. It was found that after grafting SiCNWs on the surface of carbon fibers, the strength increased from 269.7 MPa to 358.8 MPa, corresponding to an improvement of 33%. This increase was attributed to the improved interface that took advantages of the superior mechanical properties of SiCNWs.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Viney Dixit, Jacques Huot〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉In this paper we report the effect of Ti-proportion and addition of Zr-Ni on the crystal structure, morphology and hydrogen storage kinetics of Ti-V-Cr alloy. For this study, five alloys of compositions Ti〈sub〉x〈/sub〉V〈sub〉70-x〈/sub〉Cr〈sub〉30〈/sub〉 (x = 10, 20, 30, 40, 50) added with 4 wt% of 7Zr+10Ni were synthesized. Scanning electron microscopy revealed that all alloys were multiphase. X-ray powder diffraction confirmed that all the as-cast alloys have the body-centred cubic (bcc) phase as the main phase. The same amount of (7Zr+10Ni) was added in all of the alloys, but each alloy has shown a different elemental concentration in their secondary phases. For alloys x = 10 and 20, a Zr rich secondary phase was formed but for alloys x = 30, 40 and 50, the secondary phase has relatively high concentration of all elements.〈/p〉 〈p〉Upon hydrogenation, the bcc phase transformed into a face-centred cubic (fcc) phase. For x = 20, 30 and 40 a body-centred tetragonal (bct) phase was also observed along with fcc phase. Hydrogenation kinetics of all of these alloys was measured and it was found that absorption capacity increased with Ti-content. The maximum absorption capacity of 3.6 wt% was achieved for x = 50.〈/p〉 〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339574-fx1.jpg" width="256" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 776〈/p〉 〈p〉Author(s): Yu-Hua Wen, Li-Hong Zhang, Jin-Bo Wang, Rao Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Pt〈sub〉3〈/sub〉Co nanoparticles are promising catalyst candidates for fuel-cell applications because their catalytic performances are superior to pure Pt nanoparticles. Fundamental insights into the thermostability of Pt〈sub〉3〈/sub〉Co nanoparticles are critical for their syntheses, post-treatments, and ultimate applications. In this article, the thermal stability of Pt〈sub〉3〈/sub〉Co nanoparticles has been investigated by molecular dynamics simulations. Two types of structures, chemically disordered alloy and ordered intermetallic compound, are considered. Besides, two-atomic-layered Pt and Co have been introduced to coat the Pt〈sub〉3〈/sub〉Co nanoparticles to form Pt〈sub〉3〈/sub〉Co-Pt and Pt〈sub〉3〈/sub〉Co-Co core-shell nanoparticles. The simulated results reveal that the ordered intermetallic Pt〈sub〉3〈/sub〉Co nanoparticles exhibit better thermal stability than the disordered alloy ones. Pt coating is greatly superior to Co coating for improving both structural and thermal stability of Pt〈sub〉3〈/sub〉Co nanoparticles. For Pt〈sub〉3〈/sub〉Co and Pt coated Pt〈sub〉3〈/sub〉Co nanoparticles, the overall melting simultaneously happens in both Pt and Co. However, Co-coated surface induces the two-stage melting of Pt〈sub〉3〈/sub〉Co nanoparticles at large sizes; it markedly decreases the thermal stability of the nanoparticles at small sizes, resulting in the melting point even lower than pure Co ones. The remarkably lowered melting temperature is associated with the order-to-disorder transformation in the Co-coated shell and the appreciable change of particle shape before surface premelting.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339495-fx1.jpg" width="257" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Farsad Forghani, Jong Chan Han, Jongun Moon, Reza Abbaschian, Chan Gyung Park, Hyoung Seop Kim, Mahmoud Nili-Ahmadabadi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Order-disorder coherent interfaces determine the microstructure and mechanical properties of precipitation-hardened high-temperature alloys. The characteristics of these interfaces can be defined by a compositional width, δ, and structural width, δ′. The latter, which can be considered as the width of the ordered part of the interface, can play an important role in high-temperature mechanical behavior of precipitation-hardened alloys. This is due to the fact that diffusion in the ordered part of the interface is generally much slower than diffusion in the disordered phase, thus hindering the solid-state diffusion-based phenomena. Here, we investigate the order-disorder interface in a Ni-19Al (at.%) alloy as a model alloy for Ni-based superalloys using atomic-resolution scanning transmission electron microscopy and three-dimensional atom probe tomography. Then, we employ thermodynamic modeling to describe the interplay between the structural and compositional interface widths in binary Ni-Al and in ternary Ni-Al-Cr and Co-Al-W systems. We introduce the δ′/δ ratio as a critical parameter that varies significantly in different alloys. Our findings offer a general pathway to control the δ′/δ ratio of interfaces, which in turn affect the high-temperature properties of precipitation-hardened alloys.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Pradeep Chavan, L.R. Naik, P.B. Belavi, Geeta Chavan, V.T. Muttannavar, B.K. Bammannavar, R.K. Kotnala〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The magnetoelectric composites with the compositions of ferrites & ferroelectrics having the general chemical formula (x) Ni〈sub〉0.8〈/sub〉Mg〈sub〉0.2〈/sub〉Fe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 + (1-x) BaZr〈sub〉0.2〈/sub〉Ti〈sub〉0.8〈/sub〉O〈sub〉3〈/sub〉 (in which x = 0.1, 0.2, 0.3) were synthesized by using double sintering ceramic technique. From XRD, the phase formation of ferrites with cubic structure and ferroelectrics with tetragonal perovskite structure was confirmed through the measurement of XRD. The two phase ME composites have larger saturation magnetization and dielectric constant; it is because of the effect of interfacial strain on BaZr〈sub〉0.2〈/sub〉Ti〈sub〉0.8〈/sub〉O〈sub〉3〈/sub〉 ferroelectric phase. Furthermore, the ME response 4.262 mVcm〈sup〉−1〈/sup〉Oe〈sup〉−1〈/sup〉 was observed for (30%) Ni〈sub〉0.8〈/sub〉Mg〈sub〉0.2〈/sub〉Fe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 + (70%) BaZr〈sub〉0〈em〉.〈/em〉2〈/sub〉Ti〈sub〉0〈em〉.〈/em〉8〈/sub〉O〈sub〉3〈/sub〉 composites at 5.0 kOe applied DC magnetic field; it shows the success of magnetic control of the dielectric response via the mechanical coupling which can be exploited in the future applications of multiferroic composites.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Yuliang Zhao, Zhi Wang, Chun Zhang, Weiwen Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of Fe content on the three-dimensional (3D) morphologies of Fe-rich intermetallic phases (Fe phases), Al〈sub〉2〈/sub〉Cu, and pores and mechanical properties of cast Al-5.0Cu-0.6Mn alloys with 0.5 and 1.0 wt % Fe are characterized using synchrotron X-ray tomography and a tensile test. The results show that both Fe phases and Al〈sub〉2〈/sub〉Cu exhibit a complex 3D network structure, and the pores are irregular with complex interconnected and near-globular shape. As the Fe content increases from 0.5% to 1.0%, the volume fraction and equivalent diameter of Fe phases increase, whereas both their interconnectivities decrease. Skeletonization analysis shows that the Chinese-script-shaped Fe phase is more compacted than the plate-like Fe phases. The equivalent diameter and sphericity of pores vary with Fe content, and their relationships follow exponential functions. The addition of Fe results in a decrease in the ultimate tensile strength and elongation from 224 MPa to 200 MPa and from 5.5% to 3.6%, respectively, owing to increasing volume fraction of sharp-edged Fe phases and pores, resulting in stress concentration during tensile test.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881834026X-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Jiabin Zhang, Ruiwen Shu, Yanpei Ma, Xiayu Tang, Gengyuan Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Herein, the iron ions doped tin dioxide/reduced graphene oxide (Fe-doped SnO〈sub〉2〈/sub〉/RGO) nanocomposites were fabricated by a facile one-step hydrothermal strategy. The structure, composition, micromorphology, and electromagnetic parameters of the obtained nanocomposites were systematically investigated by various analysis techniques. Results revealed that the doping of Fe〈sup〉3+〈/sup〉 ion had notable effect on the structure and electromagnetic wave (EMW) absorption properties of SnO〈sub〉2〈/sub〉/RGO nanocomposites. The as-prepared Fe-doped SnO〈sub〉2〈/sub〉/RGO nanocomposites showed the minimum reflection loss (〈em〉RL〈/em〉〈sub〉min〈/sub〉) of −29.0 dB and effective absorption bandwidth (EAB, 〈em〉RL〈/em〉 ≤ −10 dB) of 2.7 GHz. Significantly, the dual-waveband absorption characteristic almost covering the C and Ku bands was observed. Besides, the possible EMW absorption mechanism was further proposed. Our results could be helpful for the designing and developing novel graphene-based nanocomposites as the high-performance EMW absorbers.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S092583881834221X-fx1.jpg" width="245" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Jingjing Liu, Shuai Zhu, Honghui Cheng, Zhi Zheng, Zhida Zhu, Kai Yan, Shumin Han〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, various amounts of (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase is successfully produced in a A〈sub〉2〈/sub〉B〈sub〉7〈/sub〉-type La〈sub〉0.75〈/sub〉Mg〈sub〉0.25〈/sub〉Ni〈sub〉3.5〈/sub〉 alloy by zone heating the as-cast alloy at the peritectic reaction temperature of the (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase (1203 K) for different durations. The formation process, electrochemical effects and functioning mechanism of the (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase are studied. The as-cast alloy contains (La,Mg)〈sub〉2〈/sub〉Ni〈sub〉7〈/sub〉 and LaNi〈sub〉5〈/sub〉 main phases, and (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 minor phase. During zone heating, the peritectic reaction between the LaNi〈sub〉5〈/sub〉 solid phase and the melted (La,Mg)〈sub〉2〈/sub〉Ni〈sub〉7〈/sub〉 liquid phase occurs, forming (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase. Thus the (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase abundance increases from 9.8 wt% (as-cast) to 46.2 wt% (heated for 24 h). The hydrogen desorption plateau pressure of the alloys increases with increasing (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase abundance, contributing to fast hydrogen desorption and large current dischargeability. In addition, the (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase network in the alloy matrix has a good structural stability against repeated hydrogen absorption/desorption, keeping the alloy from serious lattice destruction and crystal defects. Moreover, the discrete expansion/contraction between the LaNi〈sub〉5〈/sub〉 phase and the superlattice phases during cycling decreases with the consumption of the LaNi〈sub〉5〈/sub〉 phase, which relives the alloys' pulverization, and thus enhancing the oxidation resistance. Thereby, the cycling stability of the alloy electrodes of the 150〈sup〉th〈/sup〉 cycle increases from 65.4% (9.8 wt% (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase) to 80.4% (46.2 wt% (La,Mg)〈sub〉5〈/sub〉Ni〈sub〉19〈/sub〉 phase).〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818342154-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Run Cui, Yu Han, Zhixiang Zhu, Baoan Chen, Yi Ding, Qiang Zhang, Qiang Wang, Guang Ma, Feng Pei, Zhiguo Ye〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the rapid development of ultrahigh voltage engineering (〉500 kV), it has been increasingly difficult to satisfy the high requirements of traditional electrical contact materials for ultrahigh voltage circuit breakers. The copper/graphene (Cu/G) composite coatings on a pure copper substrate are successfully fabricated using a facile method of cathodic co-electrodeposition. The morphology, structure, coating composition and porosity of the Cu/G composite coatings were studied. The Vickers hardness of the Cu/G composite coating shows an increase of approximately 25% compared to a pure copper coating. The addition of graphene in the composite coating with a low friction factor of approximately 0.2 improves the wear resistance. The thermal conductivity of the Cu/G composite coating prepared in a plating solution of 10 g L〈sup〉−1〈/sup〉 graphene content reaches 285.2 W m〈sup〉−1〈/sup〉 k〈sup〉−1〈/sup〉 at room temperature, which is an increase of 61.9% compared to a pure copper coating. The average chopping current (3.6 A) of the Cu/G composite coating is superior to that of the Cu20W80 alloy, indicating an improved arc ablation resistance. The Cu/G composite coating provides new possibilities to replace the traditional electrical contact materials of ultrahigh voltage circuit breakers.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Shi-Jian Liu, Yi-Chao Zou, Xiao-Lei Shi, Qi-Zhen Li, Yu-Zhe Yang, Wei-Di Liu, Zhi-Gang Chen, Jin Zou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we synthesized Mo〈sub〉0.9〈/sub〉W〈sub〉0.1〈/sub〉Te〈sub〉2〈/sub〉 nanobelts on the SiO〈sub〉2〈/sub〉/Si substrates without using catalyst by a facile chemical vapour deposition method. Through detailed structural and compositional characterizations, we found that Mo〈sub〉0.9〈/sub〉W〈sub〉0.1〈/sub〉Te〈sub〉2〈/sub〉 nanobelts have a thickness of ∼50 nm with a width-to-thickness ratio of 3–5 and a length up to tens of μm. Besides, the grown nanobelts have a monoclinic structure with a growth direction of [010] and the {001} belt surface. Moreover, a vapour-solid growth mechanism is proposed to explain the growth of Mo〈sub〉0.9〈/sub〉W〈sub〉0.1〈/sub〉Te〈sub〉2〈/sub〉 nanobelts. This study demonstrated a simple synthesis method for the growth of single crystalline Mo〈sub〉〈em〉x〈/em〉〈/sub〉W〈sub〉1-〈em〉x〈/em〉〈/sub〉Te〈sub〉2〈/sub〉 nanomaterials, which is significant for the development of Mo〈sub〉〈em〉x〈/em〉〈/sub〉W〈sub〉1-〈em〉x〈/em〉〈/sub〉Te〈sub〉2〈/sub〉-based electronic and spintronic devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Jiabin Chen, Shujuan Tan, Xiaohui Liang, Wei Liu, Guangbin Ji〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we report a facile method to prepare rod-like Te material, which can be used as a novel microwave absorber. Diameter of the Te rods can be tuned in the range of 46–51 nm by changing the reaction time. With the increase of Te particle diameter in the composites, the microwave absorbing property gets worse. As for the Te-0.5 sample with diameter of 45.7 nm, a maximum reflection loss value of −53.8 dB at 16.0 GHz and an effective absorption bandwidth (4.8 GHz) ranging from 13.2 to 18 GHz at the thickness of only 1.55 mm can be achieved. To the best of our knowledge, it is the first time to investigate the microwave response of Te rods. These rods show obvious potential for lightweight, highly efficient microwave absorption in high frequency.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Qian Liu, Aimei Gao, Yulan Huang, Fenyun Yi, Honghong cheng, Shixu Zhao, Hongyu Chen, Ronghua Zeng, Ziqi Sun, Dong Shu, Xiaona Song〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new type of sandwiched nanosheets 3D MoS〈sub〉2〈/sub〉/C@RGO is synthesized by supramolecular self-assembly methods, as a novel and excellence electrode material. The surface characterization techniques show that the sandwiched 3D MoS〈sub〉2〈/sub〉/C@RGO possesses rich porosity and large specific area, which is convenient for electrolyte ion transportation and beneficial for the improved electrical conductivity. An outstanding specific capacitance of the prepared MoS〈sub〉2〈/sub〉/C@RGO of 340.0 F/g at 1 A g〈sup〉−1〈/sup〉 is achieved with an excellent cycle stability of 90% after 1000 cycles at the scanning rate of 40 mV/s. The sandwiched 3D MoS〈sub〉2〈/sub〉/C@RGO is suggested to be an ideal candidate for supercapacitors.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818342294-fx1.jpg" width="291" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Yu Zhang, Xiaopeng Wang, Fantao Kong, Liangliang Sun, Yuyong Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Using the hot-pack rolling method, β-solidifying Ti-43Al-9V-0.2Y alloy sheets were rolled (thickness reduction: 85%) within the α(α〈sub〉2〈/sub〉) + β + γ ternary-phase region at temperatures ranging from 1100 °C to 1200 °C. The microstructure and texture evolution occurring during dynamic recrystallization of the γ phase and their effect on the mechanical properties were systematically investigated. After hot-rolling, residual lamellar structures of the as-forged TiAl alloy were completely broken down and the fraction of dynamically recrystallized grains increased significantly with increasing rolling temperature. Lower-temperature and higher-temperature rolling were conducive for dynamic-recrystallization nucleation and growth, respectively, of the γ grains. At 1100 °C, the precipitation of numerous fine (thickness: ∼200 nm) γ laths from the β-phase ribbon was accompanied by the emergence of γ twins in the new grains. The texture evolution was also strongly dependent on the hot-rolling temperature, as evidenced by the transformation of recrystallization textures into random deformation components when the temperature was increased to 1200 °C. Moreover, compared with those rolled at higher temperatures, the sheet hot-rolled at 1100 °C had a significantly higher tensile strength (ultimate tensile strength (UTS): 945 MPa, yield strength (YS): 840 MPa) at room temperature. A good combination of high strength (UTS: 550 MPa, YS: 480 MPa) and sufficient ductility (80%) of this alloy sheet was also achieved at 750 °C.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Dengkui Zhang, Guoqing Wang, Aiping Wu, Yue Zhao, Quan Li, Xianli Liu, Danyang Meng, Jianling Song, Zhongping Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The strength and plasticity of 2219 aluminium alloy tungsten inert gas (TIG)-welded joints are inconsistent, which can compromise the safety of products. Both numerical simulation and experimental methods are used to study why the mechanical properties show a significant variation among 2219 aluminium alloy TIG-welded joints; the reasons can be summarized as involving geometric factors and metallurgical factors. Changes in the front weld width, the penetration depth of the capping weld, and other geometric parameters can have different effects on joints' mechanical properties. Three types of metallurgical factors can negatively affect joints' mechanical properties: i) unfavourable eutectic structure (the presence of coarsened eutectic particles and a thickened grain boundary eutectic structure in the crack initiation region of C10S+C10S welded joints; and the appearance of a continuously elongated eutectic structure close to the fusion line near the crack initiation region of C10S+CYS-welded joints); ii) significant segregation in the weld zone (WZ); and iii) decreased microhardness values in the partially melted zone (PMZ) and in the WZ. Two methods can be adopted to improve the joints' mechanical properties: i) The shapes of the welded joints can be optimized by adjusting the welding process parameters. One example is decreasing the penetration depth of the capping weld by decreasing the welding current and gas flow rate during the second pass. ii) The degree of segregation in the WZ and PMZ can be reduced by properly adjusting the welding heat input and wire feeding speed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Peng Wan, Kelu Wang, Hang Zou, Shiqiang Lu, Xin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The isothermal constant strain rate compression test of Ti-10.2Mo-4.9Zr-5.5Sn alloy was carried out by Gleeble-3500 thermomechanical simulator. The hot deformation behavior at temperature of 670–820 °C and strain rate of 0.001–10s〈sup〉−1〈/sup〉 was studied, and the activation energy of hot deformation was calculated. The results show that the flow stress of the alloy is more sensitive to the deformation temperature and strain rate, and is reduced by the increase of the deformation temperature and the decrease of the strain rate; the activation energy of the hot deformation of the alloy is higher than the self-diffusion activation energy of pure α titanium and pure β titanium alloy. According to the error calculation, the correlation coefficient and the average relative error of the constitutive model of Ti-10.2Mo-4.9Zr-5.5Sn alloy established by strain compensation are 0.9716 and 6.24%, and they own good precision. Based on the hot processing map of the Ti-10.2Mo-4.9Zr-5.5Sn alloy set up by the dynamic material model, instability zone's unstable form is mainly local flow and stable zone's deformation mechanism is mainly dynamic recovery and dynamic recrystallization through analyzing stable and unstable zones' microstructure; and it is found that the suitable deformation parameters of Ti-10.2Mo-4.9Zr-5.5Sn alloy are as follows: deformation temperature 670–700 °C, strain rate 0.001–0.003s〈sup〉−1〈/sup〉, deformation temperature 790–820 °C, and strain rate 0.001–0.1s〈sup〉−1〈/sup〉 through the processing map and microstructure observation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Polina Metalnikov, Guy Ben-Hamu, Dan Eliezer, Kwang Seon Shin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The effect of Sn additions on the microstructure and corrosion behavior of new wrought Mg-5Al-xSn (x = 0.71, 1.47, 2.44, and 3.09 wt%) was studied through optical and electron microscopy, XRD, hydrogen evolution test, and electrochemical measurements. Increasing of the Sn content was followed an increase in the quantity of Sn dissolved in the Mg matrix and precipitation of Mg〈sub〉2〈/sub〉Sn intermetallics when Sn content exceeded 1.47 wt%. The corrosion mode in a short immersion period was pitting corrosion; presence of cathodic sites (i.e., Mg〈sub〉2〈/sub〉Sn intermetallics) deteriorated the alloys' corrosion resistance. However, with a long immersion period the corrosion mode of the alloys with Sn content above 0.71 wt% was mixed pitting and filiform corrosion, indicating that a passivation layer was formed on the alloys' surface and increased their corrosion resistance.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Elyorjon Jumaev, Sung Hwan Hong, Jeong Tae Kim, Hae Jin Park, Young Seok Kim, Sang Chul Mun, Jun-Young Park, Gian Song, Jong Kook Lee, Byung Ho Min, Taegyu Lee, Ki Buem Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quaternary AlCoCrNi alloy was designed by removing the heavy constituent of Fe from the dual-phase AlCoCrFeNi high-entropy alloy to achieve low density with good mechanical properties. The AlCoCrNi alloy exhibited a nano-scale dual-phase structure consisted of Cr-rich A2 and Ni(Co)-Al-rich B2 phases with a high degree of coherence in both dendritic and interdendritic regions. In particular, the Ni(Co)-Al-rich B2 phase revealed the non-stoichiometric composition between the Ni and the Al, which deviated with the Ni-Al-rich B2 phase with a stoichiometric composition in the previous AlCoCrFeNi high-entropy alloy. The chemical evolution in the constituent phases strongly affected the mechanical properties of the dual-phase high-entropy alloy. Based on these microstructural features of the AlCoCrNi alloy, the mechanical properties were systematically investigated at wide temperature ranges.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818341781-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Yiyu Zhan, Yahong Jin, Haoyi Wu, Lifang Yuan, Guifang Ju, Yang Lv, Yihua Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new near-infrared phosphor Mg〈sub〉4〈/sub〉Ga〈sub〉4〈/sub〉Ge〈sub〉3〈/sub〉O〈sub〉16〈/sub〉: Cr〈sup〉3+〈/sup〉 with multi-photo-functionalities has been developed. Such phosphors can act as luminescent down-shifting materials converting UV and visible photons into NIR light (600–850 nm). UV irradiation induced strong NIR long persistent luminescence (LPL) can persist for more than 10 h. With the prolonged decay time, the extinguished NIR LPL can be rejuvenated by external photo stimulus including not only 980 nm light but also visible light. Such NIR photostimulated persistent luminescence (PSPL) presents separated write-in and read-out wavelength ranges. Meanwhile, photochromism (PC), that the material surface undergoes reversible change between white/pale green and ronbrown when triggered alternatively by UV and visible irradiation/heating, was also observed. Several recycle measurements demonstrate the robust fatigue resistance of PC property. Owning to the multi-photo-functionalities of Mg〈sub〉4〈/sub〉Ga〈sub〉4〈/sub〉Ge〈sub〉3〈/sub〉O〈sub〉16〈/sub〉: Cr〈sup〉3+〈/sup〉, the fabrication of flexible phosphor membranes endows their application for optical information storage and repeatable optical recording. The electron motion in traps was studied by thermoluminescence (TL) and the color center formation was verified with electron spin resonance (ESR) spectra, based on which an energy level diagram was proposed for the illustration of the multifunctional mechanism. The revealing of multi-photo-functional mechanism and fabrication of flexible phosphor membranes may promote the development of a universal design principle for further study.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818341860-fx1.jpg" width="392" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Mingji Zhang, Jieyi Yu, Tongpan Ying, Jiahao Yu, Yuping Sun, Xianguo Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Except for low conductivity and huge volume expansion, FeP can be considered as a promising anode material for lithium ion batteries (LIBs). For overcoming these issues, P doped onion-like carbon layers coated FeP (FeP@(P, OLC)) nanoparticles have been one-pot prepared by arc discharging the Fe-P powers under the gas mixture of argon, hydrogen and ethanol, which have been designed for achieving excellent performance anode in LIBs. Being applied as anode material for LIBs, FeP@(P, OLC) core-shell structured nanoparticles deliver superior electrochemical performance by means of high initial coulombic efficiency (79.8%), stable cycle life (915 mA h g〈sup〉−1〈/sup〉 at 0.1 A g〈sup〉−1〈/sup〉 after 500 cycles) and excellent rate capability (averaged capacities of 379 and 237 mA h g〈sup〉−1〈/sup〉 at 8.0 and 10.0 A g〈sup〉−1〈/sup〉, respectively), which are ascribed to the synergistic effect of microstructure design and the composition optimization. P-doped OLC shells can alleviate the aggregation of FeP nanoparticles, offer the efficient channels for electrons and ions, and buffer the volumetric variety for FeP nanoparticles during the repetitive Li ion insertion/extraction process, avoiding partially the pulverization issue and improving cyclic stability. The facile synthesis strategy is expected to be helpful for designing and preparing transition metal phosphide nanoparticles coated by P doped OLC shell for energy storage applications.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Xiaoguang Huang, Heechul Woo, Peinian Wu, Qin Wang, Guolong Tan, Jin Woo Choi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Environmentally harmless Antimony sulfide (Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉) photoanode introduced water splitting device have a great potential for producing hydrogen from its optical characteristic. However, fabrication of highly pure Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 film by solution process has been suppressed due to the presence of various sulfide antimony compounds while chemical synthesis process. Here, high phase purity and high crystallinity Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 nanocrystal was successfully fabricated by mechanical alloying method. The solvent free and simple fabrication process realized low manufacturing cost of Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 nanocrystal fabrication without environmental hazard. Optical characterization by XRD, XPS and Raman spectroscopy confirmed that Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 nanocrystal film has high phase purity with high crystallinity. Furthermore, observed SEM images shows that fabricated Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 nanocrystal based nanostructure has high thermal stability till 300 °C. Finally, nanostructured Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 photoanode introduced water splitting device presented a saturation photocurrent of 0.69 mA cm〈sup〉−2〈/sup〉 at 1.9 V versus the reversible hydrogen electrode (RHE) in 0.5 M H〈sub〉2〈/sub〉SO〈sub〉4〈/sub〉 under 1-sun illumination, with high stability and 〈em〉Ф〈/em〉〈sub〉saved, NPAC〈/sub〉 value, 4.36%. High photocurrent of water splitting device is originated from enlarged surface area of Sb〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 nanocrystal film and electrical conduction improvement due to thermal annealing which reduced imperfections between nanoparticles.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Zhen Tian, Jiahuan Yin, Xiaomin Wang, Yongzhen Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Designing nano-composite with elaborate structure is an effective way for enhancing the electrochemical performance. Herein, the nickel sulfide (Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉) nanosheets covered by reduced graphene oxide (rGO) are synthesized directly on the carbon cloth (CC) via an ion-exchange method. The Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 nanosheets are uniformly arranged on CC matrix, benefitting the electrochemical activity, and the introduced rGO enable the additional ion transport path and prevent Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉 from dissolving into electrolyte during the cycling process. As a result, this elaborately designed rGO@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/CC electrode demonstrates a high capacity of 477.37C g〈sup〉−1〈/sup〉 at a density current of 2 A g〈sup〉−1〈/sup〉 and a decent stability of 88% retention after 5000 cycles. Furthermore, a flexible asymmetric supercapacitor (FASC) is assembled using rGO@Ni〈sub〉3〈/sub〉S〈sub〉2〈/sub〉/CC as electrode, showing its great potential in portable supercapacitors.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): А.V. Dmitriev, Е.V. Vladimirova, M.V. Kandaurov, D.G. Kellerman, M.V. Kuznetsov, L.U. Buldakova, R.F. Samigullina〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Single-phase powders of bismuth ferrite have been synthesized for the first time by ultrasonic spray pyrolysis from nitrate solution in the presence of tartaric acid. The produced powders consist of hollow spherical agglomerates with a mean diameter of ∼1 μm. The influence of tartaric acid concentration on the synthesis temperature and morphology of hollow spheres was established. The agglomerate shells have open and closed pores. The mean values of the shell thickness and the ratios of closed and open pores were estimated and their dependence on the concentration of tartaric acid was found. It was shown that the magnetic properties are determined not only by the size of nanoparticles composing the agglomerates, but also by the morphology of hollow sphere shells.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818340908-fx1.jpg" width="276" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Wei Chen, Ruiyi Li, Zaijun Li, Yongqiang Yang, Haiyan Zhu, Junkang Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hybrid of graphene with metal oxide has become one research hotspot in material science, because the hybrid may pave one new way to improve their electronic, chemical and electrochemical properties. The study reports one strategy for synthesis of copper oxide-histidine functionalized graphene quantum dots (CuO-His-GQD). First, Cu〈sup〉2+〈/sup〉 ions react with His-GQDs to form Cu-His-GQD complex via the coordination between Cu〈sup〉2+〈/sup〉 and His-GQD. The complex is oxidized in air to produce CuO-His-GQD hybrid. The as-prepared hybrid offers one three-dimensional architecture with the rich of open-porous structures. As the intimate chemical and electrical contact between the CuO and the His-GQDs was achieved, the hybrid of CuO with His-GQD creates a significant amplification of detection signal. The modified glass carbon electrode based on the CuO-His-GQD was used for differential pulse voltammetric detection of hydroquinone. Figures of merit include a wide linear response range (0.001–40 μM) and a 0.31 nM limit of detection at S/N ratio of 3. The sensor has been successfully applied in determination of hydroquinone in natural water samples. In addition, the study also provides an approach for fabrication of metal oxide-based nanocomposites with excellent electrochemical performance for sensing, catalysis, supercapacitors and lithium ion batteries.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818339239-fx1.jpg" width="406" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Elif Ceylan Cengiz, Omer Salihoglu, Osman Ozturk, Coskun Kocabas, Rezan Demir-Cakan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lithium-Sulfur (Li-S) batteries are known for their high energy density and cost-effectiveness. However, the Li-S chemistry is a challenging topic due to the shuttle effect and the use of highly reactive lithium metal anode. To solve these issues, ultra-lightweight multilayered graphene coated paper separator is proposed as an interlayer. The interlayer is firstly coated on nickel foil by Chemical Vapor Deposition (CVD) method followed by transferring to the paper by fishing process. By employing this unique technique, a very light (∼8 μg/cm〈sup〉2〈/sup〉) graphene coating layer is obtained which does not further imply lowering the entire energy density of the cell. As a whole, the cell with graphene coated paper exhibits 610 mAh/g discharge capacity at C/5 after 100 cycles, while the cell without interlayer exhibits much poorer performance. The improved performance is mostly associated with the interaction between graphene and polysulfide species which is proven by X-Ray Photoelectron Spectroscopy measurement as well as the excellent electronic conductivity of graphene layer which behaves as a secondary current collector resulting the cell resistance decrease.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818341926-fx1.jpg" width="402" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Zejie Zhang, Debi Zhou, Xinjun Bao, Gonghong Huang, Qiang Tang, Boyun Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Mn/C catalysts for oxygen reduction reaction (ORR) were prepared by a facile method, the as-prepared material synthesized at 300 °C for 2 h exhibits splendid catalytic activity for ORR along with ascendant long-term durability, the current density of the Mn-300-2/C electrode is 119 mA cm〈sup〉−2〈/sup〉 at −0.2 V (vs. Hg/HgO) in 6 mol L〈sup〉−1〈/sup〉 KOH electrolyte. A primary Zn-air battery was assembled using Mn-300-2/C electrode, the discharge voltage could reach up to 1.17 V at 50 mA cm〈sup〉−2〈/sup〉 and 1.07 V at a high current density of 75 mA cm〈sup〉−2〈/sup〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Y. Ustinovshikov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The article discusses previously obtained results of experimental studies of multi-component alloys, in which all components are elements of substitution. It adduces the arguments that the formation of diffusion pairs in the liquid state of the alloy is the reason that causes the very possibility of the decomposition of multi-component substitution alloys. It is shown that in substitution-intеrstitial alloys such diffusion pairs are formed only between substitution atoms, the interstitial atoms do not participate in this process in view of their very high diffusion rate at high temperatures. Electron microscopic data obtained in the article show how the ternary Fe-22% Cr-1.1% N alloy decomposes when the temperature of its heating is reduced from the liquid state to the aging temperature.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): O. Soriano-Romero, R. Lozada-Morales, U. Caldiño, A. Méndez-Blas, C. Falcony, E. Álvarez, M. Palomino-Ovando, A.N. Meza-Rocha〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Structural and spectral evaluations of Nd〈sup〉3+〈/sup〉 and Nd〈sup〉3+〈/sup〉/Yb〈sup〉3+〈/sup〉 doped CdO-V〈sub〉2〈/sub〉O〈sub〉5〈/sub〉 glasses based on X-Ray diffraction, Raman spectroscopy, absorption, excitation and emission spectra and decay time profiles, are performed. X-Ray diffraction patterns and Raman spectroscopy revealed that all samples are amorphous (glassy phase) up to 4 mol% of Yb〈sup〉3+〈/sup〉, without segregation of any crystalline phase. The optical band gap values determined from the absorption spectra, assuming direct optical band gap, were in the range of 2.13–2.07 eV, depending on the Yb〈sup〉3+〈/sup〉 concentration. The emission spectra of the Nd〈sup〉3+〈/sup〉 and Nd〈sup〉3+〈/sup〉/Yb〈sup〉3+〈/sup〉 doped glasses upon Nd〈sup〉3+〈/sup〉 excitation at 585 nm, displayed the NIR Nd〈sup〉3+〈/sup〉 feature emissions centered at 880, 1060 and 1342 nm, and Yb〈sup〉3+〈/sup〉 emission at 977 nm, being the latter one achieved at expenses of energy transfer from Nd〈sup〉3+〈/sup〉. According to the shortening of the Nd〈sup〉3+〈/sup〉 emission decay profiles such process is not radiative with efficiency in the range of 0.181–0.521, depending on the Yb〈sup〉3+〈/sup〉 content. The 880 nm Nd〈sup〉3+〈/sup〉 decay fitting using the Inokuti-Hirayama model considering, energy migration among donors, suggested that an electric dipole-dipole interaction might mediate the energy transfer process, within Nd〈sup〉3+〈/sup〉-Yb〈sup〉3+〈/sup〉 clusters.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): R. Barua, B.T. Lejeune, B.A. Jensen, L. Ke, R.W. McCallum, M.J. Kramer, L.H. Lewis〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉It is demonstrated that alloying additions of Ga and Ge enable tuning of the magnetocaloric response of the intermetallic boride AlFe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉. Samples of nominal chemical composition Al〈sub〉1.2-x〈/sub〉M〈sub〉x〈/sub〉Fe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉 (M = Ga, Ge; 〈em〉x〈/em〉 ≤ 0.30) were synthesized via suction casting (arc-melting and vacuum drawing into cylindrical copper molds) and subsequent heat treatment (annealed to 1373 K for 72 h). The saturation magnetization (〈em〉M〈/em〉〈sub〉〈em〉s〈/em〉〈/sub〉), Curie temperature (〈em〉T〈/em〉〈sub〉〈em〉c〈/em〉〈/sub〉) and specific heat capacity (〈em〉C〈/em〉〈sub〉〈em〉p〈/em〉〈/sub〉) of the samples all increase with increased Ga and/or Ge additions. Relative to the unmodified parent AlFe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉 compound, a larger than two-fold improvement in the magnetic entropy change (〈em〉Δ〈/em〉S (〈em〉μ〈/em〉〈sub〉〈em〉0〈/em〉〈/sub〉〈em〉H〈/em〉〈sub〉〈em〉app〈/em〉〈/sub〉 = 2 T) = 6.5 J kg〈sup〉−1〈/sup〉K〈sup〉−1〈/sup〉) and adiabatic temperature change (〈em〉ΔT〈/em〉〈sub〉〈em〉ad〈/em〉〈/sub〉 (〈em〉μ〈/em〉〈sub〉〈em〉0〈/em〉〈/sub〉〈em〉H〈/em〉〈sub〉〈em〉app〈/em〉〈/sub〉 = 2 T) = 2.2 K) was observed at 305 K in a sample of composition Al〈sub〉1.1〈/sub〉Ga〈sub〉0.05〈/sub〉Ge〈sub〉0.05〈/sub〉Fe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉. The enhanced magnetocaloric response of the Al〈sub〉1.2-x〈/sub〉(Ga,Ge)〈sub〉x〈/sub〉Fe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉 system is ascribed to a complex amalgamation of chemical bonding and electronic effects that arise due to Fe and Al antisite defects within the AlFe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉 lattice. Overall, these results provide insight of both fundamental and applied relevance concerning pathways for maximizing the magnetocaloric potential of AlFe〈sub〉2〈/sub〉B〈sub〉2〈/sub〉 for potential energy-related applications near room temperature.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818338805-fx1.jpg" width="359" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Fatemeh Sadat Razavi, Maryam Sadat Morassaei, Ali Salehabadi, Maryam Ghiyasiyan-Arani, Masoud Salavati-Niasari〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉With the advent of hydrogen as a vehicle fuel and with technological advances in the 1980s, various materials have been examined in order to store hydrogen. Traditional hydrogen storage requires a huge amount of initial pressure for the initial condensation of hydrogen. Nanomaterials rely not only on their intrinsic and unique features but also on their ability to act as effective immobilization matrices. Here we demonstrate a novel class of hydrogen storage nanosystems (polycrystalline Ba〈sub〉2〈/sub〉Co〈sub〉9〈/sub〉O〈sub〉14〈/sub〉) with unique structure and high power electrochemical discharge efficiencies. The Ba〈sub〉2〈/sub〉Co〈sub〉9〈/sub〉O〈sub〉14〈/sub〉 nanostructures are synthesized purely 〈em〉via〈/em〉 a well-known Pechini method in the presence of both ethylene glycol (EG) and poly(ethylene glycol)-600 (PEG-600) as a cross linking agent and space filling template, respectively, after thermal treatments. Our nanosystems consist of the particles ranging from 10 to 30 nm and average crystallite size of ∼27 nm. The electrochemical properties achieve an interesting discharge efficiency of around 850 mAh.g〈sup〉−1〈/sup〉 in 15th cycles.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818341367-fx1.jpg" width="324" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Aminul Islam, Kundan Kumar, Krishna Kant Pandey, Biswajyoti Mukherjee, O.S. Asiq Rahman, Anirban Chowdhury, Anup Kumar Keshri〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lanthanum zirconate (La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉), an emerging candidate for TBC system, faces stringent concern owing to poor fracture toughness. We report an exceptionally high fracture toughness (5.3 ± 0.4 MPa m〈sup〉0.5〈/sup〉) value for a La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 coating prepared by atmospheric plasma spray technique reinforced by carbon nanotubes (2 wt %); the enhancement in fracture toughness was noted to be more than 300% compared to all previous works. Several factors, 〈em〉viz〈/em〉. increased density, uniform distribution of CNTs in La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 matrix, stabilization of pyrochlore La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 phase and various associated toughening mechanism offered by CNTs (e.g., CNT pull out, CNT bridging and crack arresting etc.) was attributed for this surprising enhancement. In addition, splat sandwiching and nanomechanical interlocking between CNT and La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 was found to be unique toughening mechanism. Apart from it, thermal shock resistance of LZC-SD coating performed at 1300 °C, showed the 145 numbers of cycle before the partial delamination of the coating. While, it was only 87 numbers of cycle for LZ-SD coating. The density, hardness, elastic modulus values also depicted a suitable increase. The introduction of CNTs in the La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 matrix did not alter/affect any of the physical properties (phase purity, compositional integrity etc.) of the pristine La〈sub〉2〈/sub〉Zr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 system.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Xinke Liu, Yuehua Hong, Zhiwen Li, Chuyu Xu, Wei He, Usman Younis, Qiang Liu, Jing Wu, Youming Lu, V. Divakar Botcha〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉MoS〈sub〉2〈/sub〉 based hybrid structures have much attention due to their novel structures and potential applications in diverse areas, such as solar energy conversion, thermoelectric power generation and photo-transistors. In the present work, we have fabricated a novel sandwich structure of MoS〈sub〉2〈/sub〉/InSe-nanoparticles (NPs)/MoS〈sub〉2〈/sub〉 layers on SiO〈sub〉2〈/sub〉/Si substrate by a combination of chemical vapor deposition and physical vapor deposition methods. The morphology of these structures was also studied using scanning electron microscopy. In addition, we have also explored the thermal properties of these hybrid sandwich structures using temperature and power-dependent Raman spectroscopy. For MoS〈sub〉2〈/sub〉/InSe-NPs/MoS〈sub〉2〈/sub〉 sample, the first-order temperature coefficients of E〈sup〉1〈/sup〉〈sub〉2g〈/sub〉 and A〈sub〉1g〈/sub〉 modes were found to be −0.01722 and −0.01575 cm〈sup〉−1〈/sup〉/K, respectively, which are significantly large compared to MoS〈sub〉2〈/sub〉 layers without InSe-NPs (i.e. MoS〈sub〉2〈/sub〉/MoS〈sub〉2〈/sub〉 sample). Further, the thermal conductivity of MoS〈sub〉2〈/sub〉/InSe-NPs/MoS〈sub〉2〈/sub〉 and MoS〈sub〉2〈/sub〉/MoS〈sub〉2〈/sub〉 samples on SiO〈sub〉2〈/sub〉/Si substrate was extracted as ∼102.3 and ∼81.7 W/m-K, respectively. This work suggests an effective way to form a novel 2D-MoS〈sub〉2〈/sub〉 based sandwich structure with semiconductor/metal-NPs; opening up a new scenario to understand the electronic structure of the hybrid structure, and the local strain introduced by NPs. Electron-phonon interactions at an interface can have significant effects on electrical/thermal transport through the optoelectronic devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Asanee Somdee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Barium Titanate Oxide (BTO) enhanced TiO〈sub〉2〈/sub〉 nanorod array was successfully synthesized with different NaOH precipitating agent via two steps hydrothermal method. The structure and the morphology of products were characterized by XRD, SEM couple with EDS and TEM. The results showed the formation of BaTiO〈sub〉3〈/sub〉 and BaTi〈sub〉4〈/sub〉O〈sub〉9〈/sub〉 phases on the TiO〈sub〉2〈/sub〉 surface. The optical property of pure TiO〈sub〉2〈/sub〉 and BTO-TiO〈sub〉2〈/sub〉 heterostructure were investigated by UV–visible spectroscopy. The band gap of all BTO-TiO〈sub〉2〈/sub〉 samples were only slightly decreased when compared to the bare TiO〈sub〉2〈/sub〉 film. The photoconversion efficiency of the TiO〈sub〉2〈/sub〉 and BTO-TiO〈sub〉2〈/sub〉 photoanodes were measured from the J-V characteristic. The efficiency of DSSCs based on the pure TiO〈sub〉2〈/sub〉 was 2.44% while the highest performance of DSSCs based on BTO-TiO〈sub〉2〈/sub〉 was 4.29%. The charge transfer resistance and the electron lifetime (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈msub〉〈mrow〉〈mi〉τ〈/mi〉〈/mrow〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉) were further investigated by the electrochemical impedance spectroscopy (EIS). The increase of DSSCs performance is due to the better charge transfer resistance and the lower recombination during the electrons transfer across the photoanode of DSSCs, as indicated from the Nyquist and Bode plots.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Shanshan Wang, Mei Li, Wei Han, Milin Zhang, Wei Wang, Wenjuan Wang, Xiaoguang Yang, Yang Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The electrochemical formation of Ce-Ni alloy and its nucleation mechanism were researched in LiCl-KCl melts using different electrochemical methods. Cyclic voltammetric and square wave voltammetric results indicated that the electrochemical reduction of Ce (III) appeared at a less negative value on Ni electrode than that recorded on W electrode because of the formation of Ce-Ni alloy compounds. The nucleation mechanism of Ce was found to be the progressive nucleation on Ni electrode based on Scharifker-Hill model. The change of electrode surface morphology with deposited time was observed by SEM, which indicated that the morphology of Ce deposited on Ni electrode was dendritic. Ce-Ni alloys were prepared using potentiostatic electrolysis, and checked by XRD and SEM-EDS. The results showed that hydrogen storage alloys of CeNi〈sub〉2〈/sub〉, CeNi〈sub〉3〈/sub〉 and CeNi〈sub〉5〈/sub〉 were gained by controlling applied potential. Furthermore, the thermodynamic properties of Ce-Ni compounds were estimated in the temperature range of 823–898 K by open circuit chronopotentiometry.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818341197-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 10 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 777〈/p〉 〈p〉Author(s): Xiaohui Sun, Houbing Huang, Junsheng Wang, Yongqiang Wen, Zhi-Min Dang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Motivated by a broad temperature span, we performed a strain-induced broadening temperature range of electrocaloric effects in PbZr〈sub〉0.6〈/sub〉Ti〈sub〉0.4〈/sub〉O〈sub〉3〈/sub〉/PbTiO〈sub〉3〈/sub〉 ferroelectric superlattices based on phenomenological Landau-Devonshire thermodynamic theory. The results indicated that interlayer misfit strain and substrate misfit strain in superlattices modulate the Curie temperature. Considering two types of strains coexist in ferroelectric superlattices, there exist a balance between interlayer misfit strain and substrate misfit strain to broaden temperature range (281 K) of electrocaloric effects. The present study therefore contributes to the understanding of strain effects of electrocaloric cooling and provides guidance towards experimental design of high efficiency cooling devices.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Yi Lin, Change Lu, Chengyang Wei〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monoclinic BiVO〈sub〉4〈/sub〉 photocatalyst was hydrothermally synthesized at different pH conditions without surfactant. The microstructure and photocatalytic behavior of as‒prepared samples were characterized by X−ray diffraction, scanning electron microscope, transmission electron microscopy, UV–vis diffuse reflectance spectra, electrochemical workstation and dye degradation experiment. The results show that the pH value had a significant influence on the microstructure and photocatalytic performance of BiVO〈sub〉4〈/sub〉. In acid environment, heavy precipitation of tetragonal BiVO〈sub〉4〈/sub〉 took place in a short time at room temperature, whereas only amorphous powders formed as the pH value was equal or higher than 7. The monoclinic BiVO〈sub〉4〈/sub〉 gradually nucleated and grew at the early stage of synthesis procedure at 180 °C, and finally became the unique crystalline phase. The relationship between microstructure and photocatalytic activity the photocatalyst was well discussed. It is observed that the BiVO〈sub〉4〈/sub〉 prepared in the neutral condition (pH 7) exhibited desirable photocatalytic degradation efficiency toward Rhodamine B solution, mainly due to the efficient separation of photogenerated electron‒hole pairs and enhanced visual light absorption during degradation process, which were ascribed to the comprehensive function of high exposed {010} crystal facets, close packed structure, small particle size, and special floating characteristic.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): M. Saidi, S. Walha, K. Nouri, A. Kabadou, M. Jemmali, L. Bessais〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A series of Gd-Fe-Cu alloys was prepared to determine the 1073 K isothermal section of the Gd-Fe-Cu system through the use of the Scanning Electron Microscopy-Energy Dispersive X-ray spectrometry (SEM-EDS) and the X-ray Powder Diffraction (XRD) techniques. Twelve single phase regions, eleven two-phase regions, and ten three-phase regions, as well as two liquid areas were experimentally identified at 1073 K. The phase diagram at this temperature is characterized by the formation of a new ternary compound Gd〈sub〉6〈/sub〉Fe〈sub〉20.5〈/sub〉Cu〈sub〉2.5〈/sub〉 labelled A and eight binary compounds namely Gd〈sub〉2〈/sub〉Fe〈sub〉17〈/sub〉, GdFe〈sub〉3〈/sub〉, GdFe〈sub〉2〈/sub〉, GdCu, GdCu〈sub〉2〈/sub〉, GdCu〈sub〉5〈/sub〉, Gd〈sub〉0.8〈/sub〉Cu〈sub〉5.4〈/sub〉 and Hcp (GdCu). However, unlike previous studies that showed the compound Gd〈sub〉6〈/sub〉Fe〈sub〉23〈/sub〉 is stable at 1073 K, we demonstrated that it is not, and becomes stable at 1173 K. Among the eight formed binary compounds, six have extensions into the ternary system: MgCu〈sub〉2〈/sub〉-type GdFe〈sub〉2−〈em〉x〈/em〉〈/sub〉Cu〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–0.2), Th〈sub〉2〈/sub〉Zn〈sub〉17〈/sub〉-type Gd〈sub〉2〈/sub〉Fe〈sub〉17−〈em〉x〈/em〉〈/sub〉Cu〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–1.5), CsCl-type GdCu〈sub〉1−〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–0.5), KHg〈sub〉2〈/sub〉-type GdCu〈sub〉2−〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–0.6), CaCu〈sub〉5〈/sub〉-type GdCu〈sub〉5−〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–0.2) and Tb〈sub〉0.78〈/sub〉Cu〈sub〉5.44〈/sub〉-type Gd〈sub〉0.8〈/sub〉Cu〈sub〉5.4−〈em〉x〈/em〉〈/sub〉Fe〈sub〉〈em〉x〈/em〉〈/sub〉 (x = 0–0.2).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Venkatesh Pilli, Ritwik Sarkar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Alumina-carbon refractories are widely used in the continuous casting process for steelmaking due to their suitable comprehensive properties. Conventionally, these refractories contain 25-30 wt% carbon, with graphite as the major source, especially to improve corrosion and thermal shock resistances. However, the presence of high carbon encompasses several problems like high energy loss, carbon pick-up in steel, oxidation, increased CO〈sub〉2〈/sub〉 generation, etc. To avoid these issues, in the present work, alumina-carbon refractories are prepared and evaluated with reduced and fixed carbon content by partially replacing the graphite with nanocarbon. Free carbon addition is maintained at 4 wt% level by varying combination of nanocarbon and graphite content. The alumina carbon refractory compositions are processed through pressing, curing, coking, and evaluated for properties like bulk density and cold crushing strength. Phase analysis and microstructural variations in the compositions are studied along with oxidation resistance at different temperatures. Because of its smaller particle size, nanocarbon can easily fill the gaps between the other refractory particles thereby reduces porosity and improves strength. Also, greater extent of in situ aluminum carbide formation improves the strength in case of nanocarbon containing compositions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Jiajie Xu, Zhiyong Dong, Tianke Hu, Yanni Peng, Yue Situ, Hong Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An efficient visible-light-driven photocatalyst with interfacial electron transfer (IFCT) effect was prepared by introducing a facile energy level alignment in heterostructured TiO〈sub〉2〈/sub〉-Fe-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, where IFCT was promoted strongly due to the effective electron transfer. The Fe (III) clusters grafted on the TiO〈sub〉2〈/sub〉 microspheres, extended the photo response of TiO〈sub〉2〈/sub〉 from UV to visible light region, resulting in better light absorption capability. What's more, the direct transfer of photoinduced electrons from TiO〈sub〉2〈/sub〉/Fe to C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 was observed, which promoted the IFCT effect, leaving the high oxidizing holes in the valence band (VB) of TiO〈sub〉2〈/sub〉 and conduction band (CB) of C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 for further degradation. The TiO〈sub〉2〈/sub〉-Fe-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 exhibited much better photocatalytic performance for methyl orange degradation and higher photocurrent under visible light irradiation than the bare TiO〈sub〉2〈/sub〉 or C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉, which was attributed to the synergistic effect between TiO〈sub〉2〈/sub〉 and Fe/C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 as well as C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 and TiO〈sub〉2〈/sub〉/Fe. In addition, the photo-induced holes in the VB of the TiO〈sub〉2〈/sub〉 microspheres was confirmed by ESR analysis and a possible photocatalytic mechanism of TiO〈sub〉2〈/sub〉-Fe-C〈sub〉3〈/sub〉N〈sub〉4〈/sub〉 composite under visible light irradiation was also proposed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Wei Liu, Oleg D. Feya, Tekalign Terfa Debela, James R. Hester, Colin J. Webb, Evan MacA. Gray〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Zr〈sub〉3〈/sub〉Fe and Ni-substituted Zr〈sub〉3〈/sub〉Fe alloys with 30 and 50 at.% Ni were synthesized and their hydrogen absorption/desorption characteristics were compared experimentally (pressure–composition isotherms, thermal desorption spectroscopy, 〈em〉in-situ〈/em〉 neutron diffraction) and by computational methods (〈em〉ab-initio〈/em〉 molecular dynamics (AMD), nudged elastic band theory (NEB)). All the alloys absorbed hydrogen to a hydrogen-to-metal atomic ratio of about 1.7, but the hydrides formed were stable at room temperature. The Zr〈sub〉3〈/sub〉Fe〈sub〉0.5〈/sub〉Ni〈sub〉0.5〈/sub〉 alloy and its hydrided form were multi-phase. The Zr〈sub〉3〈/sub〉Fe〈sub〉0.7〈/sub〉Ni〈sub〉0.3〈/sub〉 alloy was single-phase and retained the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉C〈/mi〉〈mi〉m〈/mi〉〈mi〉c〈/mi〉〈mi〉m〈/mi〉〈/mrow〉〈/math〉 structure of the parent intermetallic. 〈em〉In-situ〈/em〉 neutron diffraction with D〈sub〉2〈/sub〉 in place of H〈sub〉2〈/sub〉 showed that the hydride formed in the isotherm measurements, Zr〈sub〉3〈/sub〉Fe〈sub〉0.7〈/sub〉Ni〈sub〉0.3〈/sub〉H〈sub〉6.88〈/sub〉, had the same structure (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mi〉C〈/mi〉〈mi〉m〈/mi〉〈mi〉c〈/mi〉〈mi〉m〈/mi〉〈/mrow〉〈/math〉) as Zr〈sub〉3〈/sub〉FeH〈sub〉7〈/sub〉, while disproportionation was observed in the hydrogenation of Zr〈sub〉3〈/sub〉Fe. The kinetics of hydride formation was slower in both the Ni-substituted alloys. Thermal desorption spectroscopy showed that substitution of 0.3Ni significantly destabilized the hydride, lowering the temperature of the principal desorption peak by about 300 K relative to Zr〈sub〉3〈/sub〉Fe–H〈sub〉2〈/sub〉, without loss of hydrogen capacity, and avoiding disproportionation. Based on the structures determined by neutron diffraction, AMD and NEB calculations were conducted to compare Zr〈sub〉3〈/sub〉Fe and Zr〈sub〉3〈/sub〉Fe〈sub〉0.7〈/sub〉Ni〈sub〉0.3〈/sub〉 and their hydrides. The AMD calculations predicted that H diffusion was slower in Ni-substituted Zr〈sub〉3〈/sub〉Fe, in agreement with the experimental observation of slower kinetics, implying a higher activation energy for H migration. The NEB calculations also predicted a higher energy barrier for H migration in Ni-substituted Zr〈sub〉3〈/sub〉Fe.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Ning Gong, Chunxing Deng, Lailei Wu, Biao Wan, Zhibin Wang, Zhiping Li, Huiyang Gou, Faming Gao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Light-metal sulfides have attracted great attention due to the technological application as energy storage devices. Combining first-principles calculations with structure searching, sulfur-rich compounds were explored theoretically in Be-S system. Interestingly, our results identify a hitherto unknown stoichiometry BeS〈sub〉2〈/sub〉 in bulk and two-dimensional (2D) configuration. With the pressure increasing, BeS〈sub〉2〈/sub〉 in bulk adopts 〈em〉P〈/em〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈mrow〉〈mover accent="true"〉〈mn〉1〈/mn〉〈mo〉¯〈/mo〉〈/mover〉〈/mrow〉〈/math〉 structure at ambient pressure, 〈em〉C〈/em〉2 phase over 1.6 GPa and then a cubic 〈em〉c〈/em〉-BeS〈sub〉2〈/sub〉 with unique S〈sub〉2〈/sub〉〈sup〉2−〈/sup〉 dimmers up to 5.8 GPa. The monolayer penta〈em〉-〈/em〉BeS〈sub〉2〈/sub〉 with Be〈sub〉2〈/sub〉S〈sub〉3〈/sub〉 pentagons and bilayer BeS structure are presented. Predicted 〈em〉c〈/em〉-BeS〈sub〉2〈/sub〉, 2D BeS〈sub〉2〈/sub〉 and BeS phases show a semiconducting character, interestingly, 〈em〉c〈/em〉-BeS〈sub〉2〈/sub〉 is found to have a direct band gap of 1.52eV. The discovery of unknown beryllium sulfides and the understanding of electronic and chemical bonding properties will provide prerequisite for the potential application in electrochemistry.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818345067-fx1.jpg" width="319" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Alloys and Compounds, Volume 781〈/p〉 〈p〉Author(s): Dami Yim, Praveen Sathiyamoorthi, Soon-Jik Hong, Hyoung Seop Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the TiC-reinforced CoCrFeMnNi high-entropy alloy (HEA) composite was fabricated using water atomization (WA), mechanical milling (MM), and spark plasma sintering (SPS). The microstructural evolution and mechanical properties of TiC-reinforced HEA composite are investigated using electron backscatter diffraction, transmission electron microscopy, and room temperature compression tests. The addition of 5 wt% of TiC nano-particles to CoCrFeMnNi HEA resulted in fine grain size, high yield strength, and high strain hardening. The average grain size achieved for alloys with and without TiC after sintering is 5.1 μm and 10.6 μm, respectively. The addition of TiC increases the compressive yield strength from ∼507 MPa to ∼698 MPa and compressive fracture strength from ∼1527 MPa to ∼2216 MPa, without sacrificing the ductility. The strengthening behavior of TiC-reinforced CoCrFeMnNi HEA composite is quantitatively discussed based on grain boundary strengthening, dislocation strengthening, and dispersion strengthening. The role of TiC nano-particles in the strain hardening improvement is investigated with respect to the dislocation-particle interaction and consequently increased dislocation density.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0925838818346668-fx1.jpg" width="500" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉