ALBERT

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 490〈/p〉 〈p〉Author(s): Ram Kumar, Jyoti Sharma, Kartik K. Iyer, E.V. Sampathkumaran〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report temperature (〈em〉T〈/em〉) dependence (2–300 K) of DC and AC magnetization (〈em〉M〈/em〉), isothermal remnant magnetization (〈em〉M〈sub〉IRM〈/sub〉〈/em〉), heat-capacity (〈em〉C〈/em〉), electrical resistivity (ρ), and magnetoresistance (MR) of a ternary intermetallic compound, Gd〈sub〉4〈/sub〉PtAl, crystallizing in a cubic (space group 〈em〉F〈/em〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"〉〈mrow〉〈mover〉〈mn〉4〈/mn〉〈mo〉-〈/mo〉〈/mover〉〈/mrow〉〈/math〉3〈em〉m〈/em〉) structure. In this structure, there are three sites for the rare-earth. The magnetization data reveal that, in addition to a magnetic transition at 64 K, there is another magnetic feature below 20 K. The 〈em〉C〈/em〉(〈em〉T〈/em〉) data reveal an upturn below 64 K, shifting to a lower temperature with increasing field, which establishes that the onset of magnetic order is of an antiferromagnetic type. However, there is no worthwhile feature near 20 K in the 〈em〉C(T)〈/em〉 curve. Ac susceptibility peak undergoes an observable change with frequency and, in particular the peak around 20 K gets suppressed with the application of a dc magnetic field; in addition, 〈em〉M〈sub〉IRM〈/sub〉〈/em〉 undergoes a slow decay with time and isothermal 〈em〉M〈/em〉 exhibits low-field hysteresis below 20 K only, which are typical of spin-glasses. The results overall suggest that this compound is a reentrant spin-glass in zero field. There are experimental signatures pointing to the existence of both antiferromagnetic and ferromagnetic components, competing with the variation of temperature and magnetic field, as a result of which electrical and magnetoresistance behaviors are peculiar. The results overall suggest that this compound exhibits interesting magnetic and transport properties.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 490〈/p〉 〈p〉Author(s): N. Leuning, S. Steentjes, M. Heller, S. Korte-Kerzel, K. Hameyer〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In material models for the finite-element simulation of electrical machines and the preceding magnetic measurements, the magnetic anisotropy of non-grain oriented electrical steel is usually considered in an oversimplified way, if at all. The magnetization behavior between rolling and transverse direction is not linear and varies with magnetic polarization, a relation that comes in addition to the complexity of the effect. In this paper, the magnetization anisotropy of five industrial non-grain oriented electrical steels is measured with a 1-D single-sheet-tester. The results are evaluated and correlated to the crystallographic texture of the studied materials. An approach to model magnetization curves at 50 Hz in arbitrary directions of the sheet plane is presented. The model is parametrized by measured magnetization curves along three different spatial directions and by macro-texture data in form of an orientation distribution function. This approach leads to a model that replicates the crossing of magnetization curves of different orientations with adequate quantitative accuracy for the application in FE magnetic field simulations.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 490〈/p〉 〈p〉Author(s): E. Saavedra, J. Escrig, J.L. Palma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The magnetization reversal process of interconnected pentagonal spin ice systems was investigated using micromagnetic simulations and experimental measurements. Five different systems were investigated, beginning with the interconnected Shakti lattice and introducing deformations with the idea of obtaining pentagonal tiling (belonging to the P4 group) until reaching an interconnected square lattice. In all pentagonal lattices, ferromagnetic domains are pinned, acting as isolated domains in an antiferromagnetic lattice, with Cairo tiling being the lattice that allows pinning more domains. Experimental measurements on a Cairo lattice of larger dimensions show that the shape of the hysteresis curve is invariant to the size of the bars that make up the interconnected pentagonal spin ice systems.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 490〈/p〉 〈p〉Author(s): H.X. Zeng, Q.X. Wang, J.S. Zhang, X.F. Liao, X.C. Zhong, H.Y. Yu, Z.W. Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different from many previous reports, La-Al-Cu alloys with different Al/Cu ratios containing only high abundant rare earth element La were employed for grain boundary diffusion treatment for sintered NdFeB permanent magnets. It is found that Al and Cu contents should be optimized to achieve coercivity enhancement. The coercivity of the magnet was enhanced from 1000 to 1006, 1077 and 1156 kA/m after La〈sub〉70〈/sub〉Al〈sub〉10〈/sub〉Cu〈sub〉20〈/sub〉, La〈sub〉70〈/sub〉Al〈sub〉15〈/sub〉Cu〈sub〉15〈/sub〉 and La〈sub〉70〈/sub〉Al〈sub〉20〈/sub〉Cu〈sub〉10〈/sub〉 alloys diffusion, at 800 °C for 1 h followed by 500 °C for 3 h. The coercivity stability was also improved, indicated by the enhanced temperature coefficient of β from −0.63 to −0.61, −0.61 and −0.60%/K. Microstructure investigation indicates that the formation of continuous grain boundary phase after diffusion reduces the magnetic exchange interaction and contributes to the enhanced coercivity. After diffusion, the La〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 phase was observed in both the triple junction and strip grain boundary. La, Al and Cu elements showed different distributions in the magnets. The diffusion coefficients obtained from Fick’s second law indicate that La diffuses faster than Al and Cu at 800 °C, which explains the various effects of the diffusion sources and different coercivity enhancements by the alloys with different Al/Cu ratios. Although the process should be further optimized, the current results demonstrate that the grain boundary diffusion using low cost La-Al-Cu alloys can improve the microstructure and enhance the coercivity of NdFeB magnets.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 22 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials〈/p〉 〈p〉Author(s): Chang-Wei Wu, Dao-Xin Yao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Two-dimensional (2D) ferromagnetic semiconductors with robust magnetism are urgently desired for nanoscale spintronics applications. However, it remains a challenge to realize them experimentally. In this work, we proposed intriguing 2D p-orbital ferromagnetic semiconductors 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si29.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉X〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si30.svg"〉〈mrow〉〈mi〉X〈/mi〉〈mo〉=〈/mo〉〈mi mathvariant="italic"〉Ca〈/mi〉〈mo〉,〈/mo〉〈mi mathvariant="italic"〉Sr〈/mi〉〈/mrow〉〈/math〉) monolayer with 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si31.svg"〉〈mrow〉〈mn〉3〈/mn〉〈msub〉〈mrow〉〈mi〉μ〈/mi〉〈/mrow〉〈mrow〉〈mi〉B〈/mi〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 magnet per unit under O surface termination using first-principles calculations. The 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si32.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉Ca〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 monolayer is bipolar magnetic material (BMS) with spin-flip gap 0.24 eV, and the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si33.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉Sr〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 is half-semiconductor (HSC) with spin-flip gap 0.31 eV, which is large enough to prevent the spin-flip transition. The Curie temperature can reach to 206 and 239 K, respectively, due to the superexchange interaction between 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si34.svg"〉〈mrow〉〈msup〉〈mrow〉〈mi〉N〈/mi〉〈/mrow〉〈mrow〉〈mo〉-〈/mo〉〈/mrow〉〈/msup〉〈/mrow〉〈/math〉 ions. The values are much higher than the boiling point of liquid nitrogen (77 K) and comparable to that of the reported 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si35.svg"〉〈mrow〉〈mi mathvariant="normal"〉ScCl〈/mi〉〈/mrow〉〈/math〉 monolayer. Moreover, the half metals are obtained via carrier doping for both the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si36.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉Ca〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si37.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉Sr〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 monolayers. In addition, the half-metallic completely spin-polarized direction of BMS 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si38.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉Ca〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 monolayer can be controlled by carrier doping type. Furthermore, the magnetism of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si39.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉X〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 monolayer is derived from p orbital, without the involvement of conventional transition metals or rare earth atoms. This is advantageous for high-speed and long-distance spin-polarization transport. These results suggest that the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si40.svg"〉〈mrow〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉X〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉NO〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/mrow〉〈/math〉 monolayer can develop spin field effect transistor for information processing and storage, and open opportunities for designing new ferromagnetic semiconductors.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0304885319322772-ga1.jpg" width="160" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 493〈/p〉 〈p〉Author(s): Chicheng Ma, Kai Liu, Xingqi Han, Sheng Yang, Nan Ye, Jiancheng Tang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The martensitic transformation (MT) and magnetocaloric properties are investigated in melt-spun Mn〈sub〉50〈/sub〉Ni〈sub〉31.5〈/sub〉Co〈sub〉8.5〈/sub〉Ti〈sub〉10〈/sub〉 all-3〈em〉d〈/em〉-metal alloy ribbons fabricated at different wheel speeds (WSs), 15, 20, and 25 m/s. All these ribbon samples reveal a coexistence of the predominant 5-layer modulated (5 M) (monoclinic, space group 〈em〉P〈/em〉2/〈em〉m〈/em〉) martensite and a small amount of non-modulated (NM) 〈em〉L〈/em〉1〈sub〉0〈/sub〉 structure (tetragonal, space group 〈em〉P〈/em〉4/〈em〉mmm〈/em〉) martensite at room temperature (RT), implying the MT temperature is above RT. With the increase of WSs from 15 to 25 m/s, the structural and magnetic parameters, such as average grain size, unit cell volume, MT temperature, and magnetic entropy change, decrease. However, it is worth noting that from 20 to 25 m/s, the reduction becomes much more sluggish or even almost stagnate in comparison with that from 15 to 20 m/s. Large effective refrigeration capacity ~79.4 J kg〈sup〉−1〈/sup〉 is obtained in sample with 20 m/s under 〈em〉μ〈/em〉〈sub〉0〈/sub〉Δ〈em〉H〈/em〉 = 0–5 T, indicating that these ribbons could be the potential candidate for magnetic refrigeration. The origins of manipulation in MT by WSs in these ribbon samples are discussed.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 493〈/p〉 〈p〉Author(s): Xiao Zhou, Ruirui Liu, Haitao Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The microstructures and soft magnetic properties of Co〈sub〉66〈/sub〉Fe〈sub〉4〈/sub〉Mo〈sub〉2〈/sub〉Si〈sub〉16〈/sub〉B〈sub〉12〈/sub〉 amorphous tape wound core were systematically investigated. The phase composition and corresponding structure evaluation of Co〈sub〉66〈/sub〉Fe〈sub〉4〈/sub〉Mo〈sub〉2〈/sub〉Si〈sub〉16〈/sub〉B〈sub〉12〈/sub〉 amorphous ribbon after annealing at various temperatures were identified firstly. In particular, at 758 K the microstructure of the ribbon is primarily composed of Co〈sub〉2〈/sub〉B, Fe〈sub〉2〈/sub〉B and β-Co phases. With the temperature approaching to 768 K, the new phases α-Co and CoSi appears. When the temperature increases to 778 K, the mixed phase combination of α(Co) + β(Co) + Co〈sub〉2〈/sub〉B + Fe〈sub〉2〈/sub〉B + CoSi exists along with an apparent nano-crystallization. The soft magnetic properties of tape wound core assembled by Co〈sub〉66〈/sub〉Fe〈sub〉4〈/sub〉Mo〈sub〉2〈/sub〉Si〈sub〉16〈/sub〉B〈sub〉12〈/sub〉 amorphous ribbon were then studied at annealed temperature from 713 K to 753 K. At 723 K, we found the permeability is highest with a maximum value of 〈em〉μ〈sub〉m〈/sub〉〈/em〉 = 1.675 × 10〈sup〉3〈/sup〉, and the coercive force is lowest with a minimum value of 0.134 Oe. The magnetization curve and the hysteresis loop of established tape would core annealed at 713–753 K remain almost unchanged. Finally, the relation between frequency and magnetic permeability and quality factor were carefully examined at different annealing temperatures.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials〈/p〉 〈p〉Author(s): Rihab Jabbar, Sabah H. Sabeeh, Awham M. Hameed〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Manganese (Mn〈sup〉+2〈/sup〉) doped spinel cobalt ferrites nanoparticles (NPs) having composition (Mn〈sub〉x〈/sub〉Co〈sub〉1-x〈/sub〉Fe〈sub〉2〈/sub〉O〈sub〉4〈/sub〉 where x = 0.2, 0.4, 0.6 and 0.8) were synthesized by sol-gel precipitation method. The structural, dielectric and magnetic properties were characterized via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), LCR meter, and vibrating sample magnetometer (VSM). The average crystallite size (D) was found to increase from 10.79 nm to 14.18 nm with increasing the Mn〈sup〉+2〈/sup〉 doping ratio from (0.2 to 0.6) then decrease to 9.95 nm with further increasing of Mn〈sup〉+2〈/sup〉 to (0.8). FTIR spectrum confirmed the formation of the spinal structure of ferrite, where the main observed bands (416.64 – 459.07 cm〈sup〉-1〈/sup〉) assigned to the octahedral complexes and (513.08 – 574.81 cm〈sup〉-1〈/sup〉) assigned to tetrahedral complexes. The dielectric properties of samples found to be decreased with increasing the doping ratio. While the hysteresis loop obtains from VSM indicated the formation of soft magnetic material and the saturation magnetization decrease from 56 emu g〈sup〉-1〈/sup〉 (Mn〈sup〉+2〈/sup〉 = 0.2) to 38 emu g〈sup〉-1〈/sup〉 (Mn〈sup〉+2〈/sup〉 = 0.8).〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 493〈/p〉 〈p〉Author(s): Yanan Zhang, Lu Li, Shunqun Liu, Diangang Pan, Lei Chen, Hong Chang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The nonmagnetic In〈sup〉3+〈/sup〉 doping in the hexagonal SrFe〈sub〉12−〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉In〈em〉〈sub〉x〈/sub〉〈/em〉O〈sub〉19〈/sub〉 (〈em〉x〈/em〉 = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1 and 2) permanent magnet increases the saturation magnetization at 300 K with the highest value up to 73.87 emu/g at 〈em〉x〈/em〉 = 0.5, and decreases it with 〈em〉x〈/em〉 〉 0.5. The coercive field keeps almost the same for 〈em〉x〈/em〉 ≤ 0.2, but it decreases with 〈em〉x〈/em〉 〉 0.2. The Curie temperature linearly decreases from 740 K for 〈em〉x〈/em〉 = 0 to 610 K for 〈em〉x〈/em〉 = 1.0, and decreases at a much lower rate to 592 K for 〈em〉x〈/em〉 = 2.0. The XPS, FT-IR and UV–vis spectra are carried out to characterize the relations between the magnetic properties and the structure. The In〈sup〉3+〈/sup〉 ions preferentially occupy the tetragonal 4f1 site, deduced from the xrd refinement and the FT-IR spectra. It is consistent with the increasing magnetization by the In〈sup〉3+〈/sup〉 doping. Oxygen vacancies exist in the compounds. The In〈sup〉3+〈/sup〉 doping and oxygen vacancies deteriorate the coercivity, while Fe〈sup〉2+〈/sup〉 ions are in favor of a high magnetocrystalline anisotropy. The energy band gap of SrFe〈sub〉12−〈/sub〉〈em〉〈sub〉x〈/sub〉〈/em〉In〈em〉〈sub〉x〈/sub〉〈/em〉O〈sub〉19〈/sub〉 increases with the increasing In〈sup〉3+〈/sup〉 doping from 1.75 eV for 〈em〉x〈/em〉 = 0 to 1.87 eV for 〈em〉x〈/em〉 = 1.0, but that of 〈em〉x〈/em〉 = 2.0 decreases to 1.79 eV. It reflects that oxygen vacancies in 〈em〉x〈/em〉 = 2.0 play a function on the energy band gap.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 January 2020〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Magnetism and Magnetic Materials, Volume 493〈/p〉 〈p〉Author(s): D.A. Petrov, R.D. Ivantsov, S.M. Zharkov, D.A. Velikanov, M.S. Molokeev, C.-R. Lin, C.-T. Tso, H.-S. Hsu, Y.-T. Tseng, E.-S. Lin, I.S. Edelman〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Effect of Ag inclusions on magnetic properties and magnetic circular dichroism (MCD) of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 nanoparticles (NPs) in the mixed system of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and Ag NPs in dependence on the relative concentration of the components is presented. The samples were synthesized by the thermal decomposition of the mixture of constant concentration of Fe(NO〈sub〉3〈/sub〉)〈sub〉3〈/sub〉·9H〈sub〉2〈/sub〉O and varied concentration of AgNO〈sub〉3〈/sub〉. The synthesized powdered samples consisted of Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 and Ag NPs located very close with each other, and in the most cases the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 NPs were bordered with the Ag nanocrystals. The Ag introducing in the samples does not effect, practically, in the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 NPs morphology and size distribution. At the same time, Ag NPs in the powdered samples cause a decrease in the Fe〈sub〉3〈/sub〉O〈sub〉4〈/sub〉 NPs magnetization and shift of the blocking temperature to lower temperatures, both approximately proportional to the Ag concentration. Most significant changes are revealed in the MCD spectra in the energy region of 1.2–2.2 eV. We have discussed the influence of the Ag NPs on the MCD spectra features in terms of the charge-transfer electron transitions.〈/p〉〈/div〉 〈/div〉