ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber (2014)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2014-08-06
    Description: Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Second-harmonic generation study of domain walls in xBi2Ti4O11-(1−x)Bi4Ti3O12 films with large dielectric permittivity (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 3172-3177 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Phase-sensitive second-harmonic generation (SHG) is employed to investigate domain patterns of c-axis oriented xBi2Ti4O11-(1−x)Bi4Ti3O12 films on SrTiO3 (001) substrates. The film density increases with increasing Bi2Ti4O11 concentration up to x=0.39. No SHG signal was observed on the Bi2Ti4O11 film. Double peaks appear in the curves of the dependence of the SHG signal on the fundamental polarization (0°–180°), which suggests the net polarization of Bi4Ti3O12 domains oriented along SrTiO3 [110] and [11¯0] directions. Under transverse electric field poling along the SrTiO3 [100] direction, the films with x=0.06 and 0.12 behave differently. The double peak intensities both increase monotonically with increasing ±E fields in the film with x=0.06. However, they change reversibly for the film at x=0.12 with increasing voltage from −2.0 to +2.1 kV. Theoretical modeling suggests the possibility of 180° wall motion with an uncorrelated phase relation for the film with x=0.06, but 90° wall motion with a complete phase relation for the film with x=0.16. The large dielectric permittivity for the film with x=0.39 is assumed to come from the 90° wall motion. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1445497
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Dielectric study in nanocrystalline Bi4Ti3O12 prepared by chemical coprecipitation (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 4878-4883 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Bi4Ti3O12 nanoparticles were synthesized by chemical coprecipitation and crystallized in the perovskite structure after calcining at 520 °C. The dielectric properties were measured in bulk nanocrystalline compacts with different grain sizes. It was found that there were three peaks in the curves of the dielectric response as a function of temperature. The first peak shifts to higher temperature with decreasing grain size, which is considered to originate from the polarization of the ions in the conductive (Bi2O2)2+ layers across the potential barrier of the weak conductive perovskitelike layers. The second peak, contributed by the polarization of the defect dipoles on the grain surfaces, especially Bii〈sup ARRANGE="STAGGER"〉.–Vo″ dipoles, decreases gradually in intensity and finally disappears with increasing grain size. The last one, corresponding to a ferroelectric phase transition temperature, increases at first with decreasing grain size from 56 to 25 nm, then decreases with further decreasing grain size, and the mechanism is correlated with a competing effect of the released internal stresses and the clamped domain walls due to the diffusion of oxygen vacancies.© 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367287
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The induced phase transformation and oxygen vacancy relaxation in La-modified bismuth titanate ceramics (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 114-116 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nanopowders of Bi2Ti2O7 with various La modifications were fabricated by chemical coprecipitation. As sintered at high temperature, the phase structure in powders translates into (La0.22Bi0.78)4Ti3O12 and (La0.26Bi0.74)2Ti4O11 with increasing La concentration, respectively. Dielectric and nonlinear resistivity investigations in bulk ceramics show that oxygen vacancy relaxation or defect dipole polarization contributes considerably to the dielectric permittivity, while the mechanism is shut off under a threshold field dependent on phase transition as well as temperature. Furthermore, the quantitative analysis of x-ray photoelectron spectroscopy indicates the deviation of oxygen element composition at surfaces of (La0.22Bi0.78)4Ti3O12 ceramic grains from the standard ratio. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.122968
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Investigations of morphotropic phase transformations in the solid solution of Bi4Ti3O12 and Bi2Ti4O11 accompanied by defect dipole orientation and oxygen vacancy migration (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 1739-1745 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nanopowders of Bi2Ti2O7 with various Na+ modifications were synthesized by chemical coprecipitation, and their phase structures transform into a solid solution of Bi4Ti3O12 and Bi2Ti4O11 after sintering at high temperature. The dielectric peak at around 517 °C in Bi4Ti3O12 is related to the domain transformation at 445 °C in Bi2Ti2O7 and at 468 °C in Bi2Ti4O11 and moves to a higher temperature with increasing Bi2Ti4O11 concentration in the solid solution. Consequently, a dramatic drop of dielectric value in the solid solution was observed under a direct current bias due to the loss of relaxation mechanisms originated from the defect dipole orientation as well as oxygen vacancy migration. Furthermore, E-field dependent resistive measurements in Bi2Ti4O11 ceramics at various temperatures assert the defect dipole rotation and oxygen vacancy migration in combination with macrodomain alignment inside grains. Especially around phase transition, the field-induced phase switching leads to the abnormal jump of resistivity. Finally, the P–E hysteresis loop measurements show a good ferroelectricity in the solid solution. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369340
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    facet.materialart.
    Unknown
    Effects of antimony (Sb) on electron trapping near SiO2/4H-SiC interfaces (2016)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2016-07-21
    Description: To investigate the mechanism by which Sb at the SiO 2 /SiC interface improves the channel mobility of 4H-SiC MOSFETs, 1 MHz capacitance measurements and constant capacitance deep level transient spectroscopy (CCDLTS) measurements were performed on Sb-implanted 4H-SiC MOS capacitors. The measurements reveal a significant concentration of Sb donors near the SiO 2 /SiC interface. Two Sb donor related CCDLTS peaks corresponding to shallow energy levels in SiC were observed close to the SiO 2 /SiC interface. Furthermore, CCDLTS measurements show that the same type of near-interface traps found in conventional dry oxide or NO-annealed capacitors are present in the Sb implanted samples. These are O1 traps, suggested to be carbon dimers substituted for O dimers in SiO 2 , and O2 traps, suggested to be interstitial Si in SiO 2 . However, electron trapping is reduced by a factor of ∼2 in Sb-implanted samples compared with samples with no Sb, primarily at energy levels within 0.2 eV of the SiC conduction band edge. This trap passivation effect is relatively small compared with the Sb-induced counter-doping effect on the MOSFET channel surface, which results in improved channel transport.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Improving z-tracking accuracy in the two-photon single-particle tracking microscope (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-10-13
    Description: Here, we present a method that can improve the z-tracking accuracy of the recently invented TSUNAMI (Tracking of Single particles Using Nonlinear And Multiplexed Illumination) microscope. This method utilizes a maximum likelihood estimator (MLE) to determine the particle's 3D position that maximizes the likelihood of the observed time-correlated photon count distribution. Our Monte Carlo simulations show that the MLE-based tracking scheme can improve the z-tracking accuracy of TSUNAMI microscope by 1.7 fold. In addition, MLE is also found to reduce the temporal correlation of the z-tracking error. Taking advantage of the smaller and less temporally correlated z-tracking error, we have precisely recovered the hybridization-melting kinetics of a DNA model system from thousands of short single-particle trajectories in silico . Our method can be generally applied to other 3D single-particle tracking techniques.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    All-fiber nonlinearity- and dispersion-managed dissipative soliton nanotube mode-locked laser (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-12-18
    Description: We report dissipative soliton generation from an Yb-doped all-fiber nonlinearity- and dispersion-managed nanotube mode-locked laser. A simple all-fiber ring cavity exploits a photonic crystal fiber for both nonlinearity enhancement and dispersion compensation. The laser generates stable dissipative solitons with large linear chirp in the net normal dispersion regime. Pulses that are 8.7 ps long are externally compressed to 118 fs, outperforming current nanotube-based Yb-doped fiber laser designs.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Gas phase synthesis of non-bundled, small diameter single-walled carbon nanotubes with near-armchair chiralities (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-07-10
    Description: We present a floating catalyst synthesis route for individual, i.e., non-bundled, small diameter single-walled carbon nanotubes (SWCNTs) with a narrow chiral angle distribution peaking at high chiralities near the armchair species. An ex situ spark discharge generator was used to form iron particles with geometric number mean diameters of 3–4 nm and fed into a laminar flow chemical vapour deposition reactor for the continuous synthesis of long and high-quality SWCNTs from ambient pressure carbon monoxide. The intensity ratio of G/D peaks in Raman spectra up to 48 and mean tube lengths up to 4  μ m were observed. The chiral distributions, as directly determined by electron diffraction in the transmission electron microscope, clustered around the (n,m) indices (7,6), (8,6), (8,7), and (9,6), with up to 70% of tubes having chiral angles over 20°. The mean diameter of SWCNTs was reduced from 1.10 to 1.04 nm by decreasing the growth temperature from 880 to 750 °C, which simultaneously increased the fraction of semiconducting tubes from 67% to 80%. Limiting the nanotube gas phase number concentration to ∼10 5  cm −3 prevented nanotube bundle formation that is due to collisions induced by Brownian diffusion. Up to 80% of 500 as-deposited tubes observed by atomic force and transmission electron microscopy were individual. Transparent conducting films deposited from these SWCNTs exhibited record low sheet resistances of 63 Ω/□ at 90% transparency for 550 nm light.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Erratum: “Deep level defects in n-type GaAsBi and GaAs grown at low temperatures” [J. Appl. Phys. 113, 133708 (2013)] (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-01-06
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...