scholarly journals Influence of Anisotropic Scattering Along the 2D-Fermi Surface on Transport Properties in an Asymmetric-Donor-Based Molecular Crystal

1993 ◽  
Vol 328 ◽  
Author(s):  
Nathanael A. Fortune ◽  
K. Murata ◽  
G. C. Papavassjuou ◽  
D. J. Lagouvardos ◽  
J. S. Zambounis
Keyword(s):  
Fermi Surface ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Hall Coefficient ◽  
Electronic Transport ◽  
Path Length ◽  
Molecular Crystal ◽  
Weak Field ◽  
Anisotropic Scattering ◽  
Hall Conductivity

ABSTRACTWe report our results for the temperature dependence of the Hall coefficient and in-plane resistivity for the asymmetric-donor-based quasi-2D Molecular crystal τ- (P-S,S-DMEDT-TTF)2 (AuBr2)1(AuBr2)y (y≈0.75). Using a recent “geometrical representation” of the weak-field 2D Hall conductivity developed by N.P. Ong [Phys. Rev. B 43, 193 (1991)], we model the temperature dependence of these electronic transport properties in terms of the temperature dependence of the scattering path length and its anisotropy along the 2D Fermi surface.

scholarly journals High-Tc Superconductors: Evidence on the Electron?Phonon Interaction from Transport Measurements

1988 ◽  
Vol 41 (4) ◽  
pp. 597 ◽  
Author(s):  
AB Kaiser ◽  
C Uher
Keyword(s):  
Thermal Conductivity ◽  
Transition Temperature ◽  
Transport Properties ◽  
Hall Coefficient ◽  
Electronic Transport ◽  
Normal State ◽  
High Tc Superconductors ◽  
Phonon Interaction ◽  
High Tc ◽  
Electron Phonon Interaction

We discuss the interpretation of measurements of thermal conductivity, thermopower, Hall coefficient, resistivity and mapetorcsistance in hiJh-temperaturc superconductors. The thermal conductivity of YBa2 Cu3 07 shows an increase below the transition temperature 7;:, demonstrating the importance of the electron-phonon interaction in reducing the phonon current in the normal state. Many features of resistivity and thermopower can be interpreted in terms of conventional metallic models, although morc exotic interpretations have been proposed. We show how measurements on morc disordered samples should help resolve controversy regarding the interpretation of the electronic transport properties.

Transport Properties of NbSe2

1974 ◽  
Vol 52 (10) ◽  
pp. 861-867 ◽  
Author(s):  
D. J. Huntley ◽  
R. F. Frindt
Keyword(s):  
Large Deviations ◽  
Phase Change ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Hall Coefficient ◽  
Band Model ◽  
Crystal Orientations ◽  
Two Band Model

The Hall coefficient, magnetoresistance, and thermoelectric power of several specimens of NbSe2 have been measured as a function of temperature for various crystal orientations. A range of behaviour of the Hall coefficient has been observed varying from a reversal at 27 K for the purest specimen to no temperature dependence for the most impure. The magnetoresistance shows large deviations from Kohler's rule which are correlated with the Hall reversal. The results are discussed in terms of a possible phase change or a two-band model.

scholarly journals Impact of Fermi Surface Shape Engineering on Calculated Electronic Transport Properties of Bi-Sb-Te

2021 ◽  
Vol 59 (1) ◽  
pp. 54-60
Author(s):  
Sang-il Kim ◽  
Jong-Chan Lim ◽  
Heesun Yang ◽  
Hyun-Sik Kim
Keyword(s):  
Electrical Conductivity ◽  
Fermi Surface ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Effective Mass ◽  
Power Factor ◽  
Electronic Transport ◽  
Surface Shape ◽  
Thermoelectric Performance ◽  
Electronic Transport Properties

Using thermoelectric refrigerators can address climate change because they do not utilize harmful greenhouse gases as refrigerants. To compete with current vapor compression cycle refrigerators, the thermoelectric performance of materials needs to be improved. However, improving thermoelectric performance is challenging because of the trade-off relationship between the Seebeck coefficient and electrical conductivity. Here, we demonstrate that decreasing conductivity effective mass by engineering the shape of the Fermi surface pocket (non-parabolicity factor) can decouple electrical conductivity from the Seebeck coefficient. The effect of engineering the non-parabolicity factor was shown by calculating the electronic transport properties of a state-of-the-art Bi-Sb-Te ingot via two-band model with varying non-parabolicity. The power factor (the product of the Seebeck coefficient squared and electrical conductivity) was calculated to be improved because of enhanced electrical conductivity, with an approximately constant Seebeck coefficient, using a non-parabolicity factor other than unity. Engineering the non-parabolicity factor to achieve lighter conductivity effective mass can improve the electronic transport properties of thermoelectric materials because it only improves electrical conductivity without decreasing the Seebeck coefficient (which is directly proportional to the band mass of a single Fermi surface pocket and not to the conductivity effective mass). Theoretically, it is demonstrated that a thermoelectric figure-of-merit <i>zT</i> higher than 1.3 can be achieved with a Bi-Sb-Te ingot if the non-parabolicity factor is engineered to be 0.2. Engineering the non-parabolicity factor is another effective band engineering approach, similar to band convergence, to achieve an effective improvement in power factor.

scholarly journals Influence of Ag2Te on Transport Properties of (AgS-bTe2)0.9(PbTe)0.1

2021 ◽  
Vol 66 (11) ◽  
pp. 983
Author(s):  
S.S. Ragimov ◽  
M.A. Musayev ◽  
N.N. Hashimova
Keyword(s):  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Temperature Interval ◽  
Hall Coefficient ◽  
Scanning Calorimetry ◽  
Maximum Value ◽  
Temperature Dependences

The transport properties of (AgSbTe2)0.9(PbTe)0.1, namely, the electrical conductivity and the Seebeck (S) and Hall (RH) coefficients, are studied in the temperature interval 80–560 K. An endothermic peak at 410 K is found by the differential scanning calorimetry (DSC). Sharp changes in the temperature dependences of the electrical conductivity and thermoelectric power in the region near 410 K are observed. The temperature dependence of Hall coefficient passes through maximum at ∼200 K and has negative sign. It is shown that, these peculiarities are due to the presence of the Ag2Te phase. The thermoelectric Z-factor has the maximum value of 2.7 × 10−3 K−1 at 400 K.

Thermoelectric and Transport Properties of In-Filled CoSb3 Skutterudites

2010 ◽  
Vol 658 ◽  
pp. 17-20 ◽  
Author(s):  
Jae Yong Jung ◽  
Kwan Ho Park ◽  
Soon Chul Ur ◽  
Il Ho Kim
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Hall Coefficient ◽  
Lattice Contribution ◽  
Type Conductivity ◽  
Semiconducting Material

In-filled CoSb3 skutterudites (InzCo4Sb12) were prepared and the filling effects on the thermoelectric and transport properties were examined. Seebeck coefficient and Hall coefficient confirmed that all the samples showed n-type conductivity. Temperature dependence of the electrical resistivity suggested that InzCo4Sb12 is a highly degenerate semiconducting material. The thermal conductivity was considerably reduced by In filling and the lattice contribution was dominant.

ELECTRONIC TRANSPORT PROPERTIES OF SILICON NANOWIRE CAGE

2018 ◽  
Author(s):  
Shenqiu Mo ◽  
Dengke Ma ◽  
Lina Yang ◽  
Meng An ◽  
Zhiyu Liu ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Silicon Nanowire ◽  
Electronic Transport Properties
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