scholarly journals The Features of Electronic Conduction in InAs

2021 ◽  
Vol 6 (3) ◽  
pp. 10-13
Author(s):  
E. Khutsishviliis ◽  
Z. Chubinishvili ◽  
G. Kekelidze ◽  
I. Kalandadze ◽  
T. Qamushadze ◽  
...  
Keyword(s):  
Zone Melting ◽  
Structural Defects ◽  
Electronic Conduction ◽  
Scattering Mechanism ◽  
Fixed Temperature ◽  
Scattering Centers ◽  
Donor Type ◽  
Before And After ◽  
Charged Point ◽  
Point Type

The electrical properties of n-type crystals of InAs compound, grown from stoichiometric melt by the horizontal zone melting method, have been investigated in the temperature range of 4.2 K-300 K before and after fast neutron irradiation up to high integral fluences of 2×1018n∙cm-2. At a fixed temperature electrons concentration (n) increases almost by one order during irradiation, and practically does not change with increasing of temperature. n increases only slightly by increasing of temperature near 300 K, both before and after irradiation. When  ≥ 4×1018cm-3 the change of  during irradiation is negligible. Comparison of experimental data of mobility with theory shows that the privileged scattering mechanism of electrons at 300 K is scattering on optical phonons in InAs with  1016-1017 cm-3 and scattering on ions of impurity in InAs with n~1018-1019 cm-3. The analysis shows that during irradiation point type scattering centers of donor-type structural defects with shallow levels in the forbidden zone appear. Consequently, the mobility decreases during irradiation. At 300 K in  sample with electrons concentration of 3×1016 cm-3 the mobility decreases by 5 times after irradiation, which is equivalent to the formation of 1.5×1019cm-3 charged point scattering centers.

scholarly journals Modification of structural and dielectric properties of polycrystalline Gd-doped BFO–PZO

2018 ◽  
Vol 08 (05) ◽  
pp. 1850031 ◽  
Author(s):  
Ambika Ray ◽  
Banarji Behera ◽  
Tanmoy Basu ◽  
Saumitra Vajandar ◽  
Santosh Kumar Satpathy ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Boundary Effect ◽  
Ion Beam ◽  
Ferroelectric Properties ◽  
Compositional Analysis ◽  
Structural Defects ◽  
X Ray ◽  
Dielectric Constant And Loss ◽  
Before And After ◽  
Lcr Meter

[Formula: see text](BiFe[Formula: see text]GdxO3)–y(PbZrO3) composites [Formula: see text], having four different Gd concentrations ([Formula: see text], 0.1, 0.15, and 0.2), were synthesized and their structural, dielectric, and ferroelectric properties have been studied using different characterization techniques. In addition, to investigate the effect of ion implantation on the microstructure and dielectric properties, these composites were exposed to 2[Formula: see text]MeV He[Formula: see text]-ions. Modifications of the structure, surface morphology and electrical properties of the samples before and after ion exposure were demonstrated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) technique, and LCR meter. The compositional analysis was carried out using energy dispersive X-ray spectrometry (EDS). XRD results demonstrated a decrease in the intensity profile of the dominant peak by a factor of 6 showing a degradation of the crystallinity. Willliamson–Hall (WH) plots reveal reduction in the grain size after irradiation along with an increase in strain and dislocation density. A decrease in the dielectric constant and loss has been recorded after ion beam exposure with reduction in ac conductivity value. The contribution of grain and grain boundary effect in conduction mechanism has been addressed using Nyquist plots. All the samples demonstrate a lossy ferroelectric loop which shows a clear modification upon irradiation. The role of structural defects modifying the physical properties of the composite materials is discussed in this work.

scholarly journals Superresolution Polarimetric ISAR Imaging Based on 2D CP-GTD Model

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Da-hai Dai ◽  
Jing-ke Zhang ◽  
Xue-song Wang ◽  
Shun-ping Xiao
Keyword(s):  
Real Data ◽  
Scattering Matrix ◽  
Geometrical Theory ◽  
Scattering Mechanism ◽  
New Approach ◽  
Scattering Centers ◽  
Isar Imaging ◽  
Geometrical Theory Of Diffraction ◽  
The One ◽  
Better Than

This paper presented a new approach to superresolution ISAR imaging based on a scattering model called coherent polarized geometrical theory of diffraction (CP-GTD) which is better matched to the physical scattering mechanism. The algorithm is a joint processing between polarization and superresolution essentially. It can also estimate the number, position, frequency dependence, span, and normalized scattering matrix of scattering centers instantaneously for each channel rather than the one which extracts parameters from each channel separately, and its performance is better than the latter because the fully polarized information is used. The superiority of the CP-GTD is verified by experiment results based on simulated and real data.

scholarly journals Bone marrow participates in the biosynthesis of human transcobalamin II

Blood ◽  
1980 ◽  
Vol 56 (3) ◽  
pp. 560-563 ◽  
Author(s):  
M Frater-Schroder ◽  
C Nissen ◽  
J Gmur ◽  
L Kierat ◽  
WH Hitzig
Keyword(s):  
Bone Marrow ◽  
Vitamin B12 ◽  
Serum Protein ◽  
Marrow Transplantation ◽  
Total Activity ◽  
Genetic Patterns ◽  
Donor Type ◽  
Before And After ◽  
Bone Marrow Derived Cells ◽  
Transcobalamin Ii

Abstract Studies concerning the site of synthesis of the vitamin B12 binding serum protein, transcobalamin II, have been done in various mammalian animals. The actual site of biosynthesis in man has not yet been defined. The finding that bone marrow derived cells release apo- transcobalamin II in the mouse led us to examine the genetic patterns of transcobalamin II in man, both before and after marrow transplantation. A gradual but incomplete transformation of the recipient's transcobalamin II type into donor's type, corresponding to 75% or less of the total activity, was registered in 4 cases. Surprisingly, persistent host-type TC II, in spite of different donor type, was observed in 4 further marrow recipients. We conclude that hematopoietic cells transferred with the transplanted marrow participate in the biosynthesis of human transcobalamin II.

Electrical Properties of InSbN Alloys Fabricated by Two-Step Ion Implantation

2012 ◽  
Vol 569 ◽  
pp. 305-310
Author(s):  
Y. Wang ◽  
D.H. Zhang ◽  
Y.J. Jin ◽  
X.Z. Chen ◽  
J.H. Li
Keyword(s):  
Electrical Properties ◽  
Ion Implantation ◽  
Carrier Concentration ◽  
Electron Concentration ◽  
Hall Mobility ◽  
Scattering Mechanism ◽  
Annealing Temperatures ◽  
Donor Type ◽  
Nitrogen Ions ◽  
Exponential Relation

We report the electrical properties of the InSbN alloys fabricated by two-step implantation of nitrogen ions into InSb wafers, characterized by Hall measurements. The alloy with higher implanted dose shows lower electron concentration due to the acceptor nature of nitrogen. At temperatures below 150 K, the electron concentration does not change and follows an exponential relation at above 200 K. The Hall mobility in all samples monotonically decreases with the increase of temperature, indicating the phonon dominating scattering mechanism. The annealing results reveal that annealing temperatures up to 598 K make the carrier concentration lower due to the reduction of donor-type defects caused by ion implantation and the acceptor nature of nitrogen.

Influence of Solidification Speed on Quality and Quantity of Structural Defects in Fe61Co10Zr2.5Hf2.5Y2W2B20 Amorphous Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 1074-1077 ◽  
Author(s):  
Marcin Nabiałek ◽  
Marcin Dośpiał ◽  
Michał Szota ◽  
Paweł Pietrusiewicz
Keyword(s):  
Amorphous Alloy ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Structural Defects ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
Linear Type ◽  
X Ray ◽  
Solidification Speed ◽  
Point Type

The microstructure of Fe61Co10Zr2,5Hf2,5Nb2W2B20 amorphous alloy in the form of ribbons obtained by classical melt spinning and plates obtained by an induction suction method were investigated using X-ray diffraction. The type of structural defects were studied by analysis of the magnetization characteristics near ferromagnetic saturation of the sample. It was shown that the presence of structural defects is strongly correlated with sample thickness and production process. It was shown that ribbons with cooling rate between 105-106 K/s have point type defects, wires obtained with lower cooling rate between 101-102 K/s, have linear type defect (quasi-dislocation dipoles). crystallization.

scholarly journals Bone marrow participates in the biosynthesis of human transcobalamin II

Blood ◽  
1980 ◽  
Vol 56 (3) ◽  
pp. 560-563
Author(s):  
M Frater-Schroder ◽  
C Nissen ◽  
J Gmur ◽  
L Kierat ◽  
WH Hitzig
Keyword(s):  
Bone Marrow ◽  
Vitamin B12 ◽  
Serum Protein ◽  
Marrow Transplantation ◽  
Total Activity ◽  
Genetic Patterns ◽  
Donor Type ◽  
Before And After ◽  
Bone Marrow Derived Cells ◽  
Transcobalamin Ii

Studies concerning the site of synthesis of the vitamin B12 binding serum protein, transcobalamin II, have been done in various mammalian animals. The actual site of biosynthesis in man has not yet been defined. The finding that bone marrow derived cells release apo- transcobalamin II in the mouse led us to examine the genetic patterns of transcobalamin II in man, both before and after marrow transplantation. A gradual but incomplete transformation of the recipient's transcobalamin II type into donor's type, corresponding to 75% or less of the total activity, was registered in 4 cases. Surprisingly, persistent host-type TC II, in spite of different donor type, was observed in 4 further marrow recipients. We conclude that hematopoietic cells transferred with the transplanted marrow participate in the biosynthesis of human transcobalamin II.

Classification of Icosahedral Quasicrystals and their Approximants by the Electronic Conduction Mechanisms

2000 ◽  
Vol 643 ◽  
Author(s):  
Tsunehiro Takeuchi ◽  
Eiichi Banno ◽  
Tomohide Onogi ◽  
Takayuki Mizunol ◽  
Takuya Sato ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Electronic Structure ◽  
Temperature Dependence ◽  
Electron Scattering ◽  
Weak Localization ◽  
Electronic Conduction ◽  
Boltzmann Transport ◽  
Scattering Mechanism ◽  
Icosahedral Quasicrystals

AbstractIn this paper, two independent factors, electronic structure at the Fermi energy and electron scattering, both of which determine the electrical resistivity, are clearly separated by using a plot of ρ4K versus RRR (RRR = ρ4K/ρ300K) for icosahedral quasicrystals and their approximants. Each contribution of the electronic structure and the electron scattering on the electrical resistivity was systematically revealed, and the origin for the high resistivities observed in the quasicrystals and approximants is well understood by taking each effect into account. We found that the quasicrystals and approximants are classified into three groups in terms of the electron scattering mechanism, which dominates the temperature dependence of the resistivity. The temperature dependence of the electrical resistivity in the first group is well understood in terms of the Boltzmann transport mechanism, and those in the second and the third groups are in terms of the weak localization and the Anderson localization, respectively.

Zone Melting Recrystallization of GaAs Films on Oxidized Si

1985 ◽  
Vol 53 ◽  
Author(s):  
Weiwen Zhu ◽  
Weiyuan Wang
Keyword(s):  
Grain Size ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Electron Mobility ◽  
Zone Melting ◽  
Hall Measurement ◽  
Signal Ratio ◽  
Before And After ◽  
Gaas Films ◽  
Diffraction Patterns

ABSTRACTIn this paper, GaAs SOI consisting of MBE deposited GaAs films on oxidized Si was recrystallized by narrow-zone melting in a RF induction graphite strip heater at a rate of 1–1.2 mm/s. The original grain size of MBE GaAs SOI films is smaller than 800 Å, and the electron diffraction patterns appear as typical polycrystalline rings as determined by SEM and ED, respectively. After zone melting recrystallization, the grain size of GaAs SOI films increases to 1 µm, the prefered ˂111˃ diffraction spots appear apparently, and the carrier concentrations and electron mobility amount to 3×1017cm−3 and 1.1×103cm2/v.s as determined by Hall measurement. The AES Ga/As signal ratio of the GaAs SO before and after recrystallization is the same as that of the GaAs single crystal. The possible application of GaAs SOI to devices is discussed.

scholarly journals Preparation and modification of inverse opal zirconia pigment

2020 ◽  
Vol 52 (3) ◽  
pp. 299-306
Author(s):  
Feng Lina ◽  
Wang Lili ◽  
Li Xiaopeng ◽  
Zhou Yemin ◽  
Wang Xiufeng ◽  
...  
Keyword(s):  
Colloidal Crystal ◽  
Nitrogen Atmosphere ◽  
Raw Material ◽  
Structural Defects ◽  
Inverse Opal ◽  
Angle Dependence ◽  
Color Saturation ◽  
Before And After ◽  
Ordered Porous

Inverse opal zirconia pigment prepared by traditional process has the disadvantages of low color saturation and variegated color which restrict its further application. In this work, the inverse opal zirconia pigment was prepared by colloidal crystal template fabricated using polystyrene microspheres with particle size of 340 ? 10 nm as raw material and further modified by sintering at 600 ?C for 2 h with heating rate of 2 ?C/min in an atmosphere tube of 0.8 L min-1 nitrogen flow. The morphology, phase crystallinity and color performance of the inverse opal zirconia pigment before and after modification were characterized in detail and the modified mechanism was investigated. The results showed that morphology of the inverse opal zirconia pigment before modification was basically a highly ordered porous structure, the phase was relatively pure, and the overall appearance was variegated color. Some parts of the samples exhibited low color saturation and different areas showed various colors, indicating that the samples had certain angle dependence. After modification, the samples showed bigger-area single blue-green color, suggesting that the color saturation was significantly improved and the angle dependence was reduced evidently. The mechanism for modification was that the zirconia precursor and polystyrene templates were carbonized when sintered in nitrogen atmosphere. The generated in-situ carbon remained in the samples and absorbed the tray background light, which significantly suppressed the multiple scattering of structural defects.

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