Electrical Transport Properties of Ga(AsxSb1−x) and (GaxIn1−x)Sb Alloys under Hydrostatic Pressure

1975 ◽  
Vol 53 (11) ◽  
pp. 1071-1077 ◽  
Author(s):  
Stanley D. Rosenbaum ◽  
John C. Woolley
Keyword(s):  
Hydrostatic Pressure ◽  
Hall Coefficient ◽  
Electrical Transport ◽  
Room Temperature ◽  
Energy Separation ◽  
Band Model ◽  
Electrical Transport Properties ◽  
Van Der Pauw ◽  
Directional Freezing ◽  
Good Agreement

Homogeneous polycrystalline n type samples of the alloys Ga(AsxSb1−x) and (GaxIn1−x)Sb have been prepared from a stoichiometric melt by directional freezing methods. Room temperature measurements of electrical conductivity and Hall coefficient as a function of hydrostatic pressure up to 12 kbars have been made on samples of different composition by means of the van der Pauw technique, all specimens used in the measurements being carefully selected to avoid the presence of grain boundary effects. The experimental curves of conductivity and Hall coefficient as a function of pressure have been fitted to a two conduction band model with various band parameters taken as adjustable. The curves thus fitted give consistent values of E12, the energy separation of the two bands, as a function of x. For (GaxIn1−x)Sb, the E12 values are in good agreement with those obtained previously from measurements as a function of temperature, no previous values having been published for Ga(AsxSb1−x). Approximate values for the coupling coefficient D12 of the alloys are also obtained.

Reinvestigation the Thermal and Electrical Transport Properties of Tl7Sb2

2013 ◽  
Vol 802 ◽  
pp. 284-288
Author(s):  
Anek Charoenphakdee ◽  
Adul Harnwangmuang ◽  
Tosawat Seetawan ◽  
Chesta Ruttanapun ◽  
Vittaya Amornkitbamrung ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Lattice Parameter ◽  
Electronic Contribution ◽  
Electrical Transport Properties ◽  
Space Group ◽  
Crystal System ◽  
Thallium Compounds

The authors examined the thermal and electrical transport properties of Tl7Sb2 at temperatures ranging from room temperature to 400 K. The crystal system of Tl7Sb2 is cubic with the lattice parameter a = 1.16053 nm and the space group is Im3m. The polycrystalline samples were prepared by melting stoichiometric amounts of thallium and antimony. Although, usually the thermal conductivity of thallium compounds is very low (<1 Wm-1K-1), that of Tl7Sb2 was relatively high (~13 Wm-1K-1 at room temperature). This is because of the large electronic contribution to the thermal conductivity.

Electrical Transport Properties of the Pentatelluride Materials Hfte5 and Zrte5

1997 ◽  
Vol 478 ◽  
Author(s):  
T. M. Tritt ◽  
M. L. Wilson ◽  
R. L. Littleton ◽  
C. Feger ◽  
J. Kolis ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Electrical Transport ◽  
Entire Range ◽  
Room Temperature ◽  
Polycrystalline Material ◽  
Polycrystalline Materials ◽  
Electrical Transport Properties ◽  
Low Dimensional ◽  
P Type

AbstractWe have measured the resistivity and thermopower of single crystals as well as polycrystalline pressed powders of the low-dimensional pentatelluride materials: HfTe5 and ZrTe5. We have performed these measurements as a function of temperature between 5K and 320K. In the single crystals there is a peak in the resistivity for both materials at a peak temperature, Tp where Tp ≈ 80K for HfTe5 and Tp ≈ 145K for ZrTe5. Both materials exhibit a large p-type thermopower around room temperature which undergoes a change to n-type below the peak. This data is similar to behavior observed previously in these materials. We have also synthesized pressed powders of polycrystalline pentatelluride materials, HfTe5 and ZrTe5. We have measured the resistivity and thermopower of these polycrystalline materials as a function of temperature between 5K and 320K. For the polycrystalline material, the room temperature thermopower for each of these materials is relatively high, +95 μV/K and +65 μV/K for HfTe5 and ZrTe5 respectively. These values compare closely to thermopower values for single crystals of these materials. At 77 K, the thermopower is +55 μV/K for HfTe5 and +35 μV/K for ZrTe5. In fact, the thermopower for the polycrystals decreases monotonically with temperature to T ≈ 5K, thus exhibiting p-type behavior over the entire range of temperature. As expected, the resistivity for the polycrystals is higher than the single crystal material, with values of 430 mΩ-cm and 24 mΩ-cm for Hfre5 and ZrTe5 respectively, compared to single crystal values of 0.35 mΩ-cm (HfTe5) and 1.0 mΩ-cm (ZrTe5). We have found that the peak in the resistivity evident in both single crystal materials is absent in these polycrystalline materials. We will discuss these materials in relation to their potential as candidates for thermoelectric applications.

High Temperature Variable Range Hopping in Heavy Al Implanted 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 283-286 ◽  
Author(s):  
Antonella Parisini ◽  
Andrea Parisini ◽  
Marco Gorni ◽  
Roberta Nipoti
Keyword(s):  
Electrical Transport ◽  
Room Temperature ◽  
Hole Transport ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Hopping Transport ◽  
Variable Range ◽  
Transmission Electron ◽  
Temperature Variable ◽  
Post Implantation

In this work, we confirm and extend the results of a previous study where a variable range hopping transport through localized impurity states has been found to dominate the electrical transport properties of 3×1020 cm-3 and 5×1020 cm-3 Al+ implanted 4H-SiC layers after 1950-2000 °C post implantation annealing. In this study, samples with longer annealing times have been taken into account. The temperature dependence of these sample conductivity follows a variable range hopping law, consistent with a nearly two-dimensional hopping transport of non-interacting carriers that in the highest doped samples, persists up to around room temperature. This result indicates that the hole transport becomes strongly anisotropic on increasing the doping level. At the origin of this unusual electrical behavior, may be the presence of basal plane stacking faults, actually observed by transmission electron microscopy in one of the 5×1020 cm-3 samples

SYNTHESIS AND CHARACTERIZATION OF COMPLEX FERROELECTRIC OXIDE

2012 ◽  
Vol 02 (04) ◽  
pp. 1250024 ◽  
Author(s):  
PIYUSH R. DAS ◽  
B. N. PARIDA ◽  
R. PADHEE ◽  
R. N. P. CHOUDHARY
Keyword(s):  
Temperature Dependence ◽  
Electrical Transport ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Ferroelectric Properties ◽  
Complex Impedance ◽  
Electrical Transport Properties ◽  
Arrhenius Behavior ◽  
Orthorhombic Crystal ◽  
Grain Distribution

The polycrystalline sample of Li2Pb2Pr2W2Ti4V4O30 was prepared by a solid-state reaction technique. The preparation conditions of the compound have been optimized using thermal analysis (DTA and TGA) technique. Room temperature structural analysis confirms the formation of single phase compound in orthorhombic crystal system. The surface morphology of the sample, recorded by scanning electron microscope, shows uniform grain distribution on the surface of the sample. The observation of hysteresis loop confirmed that the material has ferroelectric properties at room temperature. Electrical properties of the material were studied by complex impedance spectroscopic technique. Temperature dependence of electrical parameters (impedance, modulus, etc.) is strongly correlated to the micro-structural characteristics (bulk, grain boundary, etc.) of the sample. A typical temperature-dependent resistive characteristic of the sample (i.e., negative temperature coefficient of resistance (NTCR)) exhibits its semiconducting properties. The temperature dependence of dc conductivity shows a typical Arrhenius behavior. A signature of ionic conductivity in the system was observed in ac conductivity spectrum. The sample obeys Jonscher's universal power law. The hopping mechanism for electrical transport properties of the system with nonexponential-type conductivity relaxation was suggested from the electrical modulus analysis.

Ambipolar Transport Behaviors in Fullerene Peapod Transistors

2007 ◽  
Vol 121-123 ◽  
pp. 521-524 ◽  
Author(s):  
Ao Guo ◽  
Yun Yi Fu ◽  
Lun Hui Guan ◽  
Zu Jin Shi ◽  
Zhen Nan Gu ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Field Effect ◽  
Room Temperature ◽  
Field Effect Transistors ◽  
Large Percentage ◽  
C60 Fullerene ◽  
Electrical Transport Properties ◽  
Ambipolar Behavior ◽  
Ambipolar Transport

The electrical transport properties of C70 and C60 fullerene peapods are investigated. We report the fabrications and performances of field-effect transistors (FETs) based on C70 and C60 fullerene peapods. A large percentage of the fullerene peapod-FETs we fabricated exhibit ambipolar characteristics with high Ion/Ioff ratio at room temperature in air. The origin of ambipolar behavior is qualitatively discussed.

Equation of state and electrical transport properties of mixture of Li1.2Mn0.54Co0.13Ni0.13O2 and LiNi0.87Co0.09Mn0.03Al0.01O2 at high pressure

2021 ◽  
pp. 2150227
Author(s):  
Lun Xiong ◽  
Pu Tu ◽  
Yongqing Hu ◽  
Xiang Hou ◽  
Shiyun Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Electrical Transport ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Diamond Anvil

The equation of state (EOS) of mixture of Li[Formula: see text]Mn[Formula: see text]Co[Formula: see text]Ni[Formula: see text]O2 and LiNi[Formula: see text] Co[Formula: see text]Mn[Formula: see text]Al[Formula: see text]O2 was studied by synchrotron radiation X-ray diffraction (XRD) at room-temperature in a diamond anvil cell (DAC). The results showed that the hexagonal structure is maintained to the highest pressure of 23.1 GPa. The bulk modulus and its first derivative obtained from XRD data are [Formula: see text] GPa and [Formula: see text], respectively. In addition, we have investigated the high-pressure electrical conductivity of the mixture of Li[Formula: see text]Mn[Formula: see text]Co[Formula: see text]Ni[Formula: see text]O2 and LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]Al[Formula: see text]O2 to 22.9 GPa in a DAC. It is found that the resistance decreases with the increase of pressure and changes exponentially.

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