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.

The Electrical Resistivity, Thermal Conductivity, and Thermoelectric Power of Calcium from 30 K to 300 K

1975 ◽  
Vol 53 (5) ◽  
pp. 486-497 ◽  
Author(s):  
J. G. Cook ◽  
M. J. Laubitz ◽  
M. P. Van der Meer
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Band Structure ◽  
Large Deviations ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Band Model ◽  
Residual Resistance ◽  
Two Samples ◽  
Two Band Model

Data are presented for the thermal and electrical resistivity and thermoelectric power of two samples of Ca (having residual resistance ratios of 10 and 70) between 30 and 300 K. Large deviations from both Matthiessen's rule and the Wiedemann–Franz relationship are observed. The former are tentatively attributed to the presence of two distinct groups of carriers in Ca, and analyzed using the two band model. The latter deviations are interpreted as the effects of band structure. The thermoelectric power of Ca is large. In many respects the transport properties of Ca appear to be similar to those of the transition metals.

High-Temperature Transport Properties of Palladium

1972 ◽  
Vol 50 (3) ◽  
pp. 196-205 ◽  
Author(s):  
M. J. Laubitz ◽  
T. Matsumura
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Large Deviations ◽  
Thermoelectric Power ◽  
The Other ◽  
Band Model ◽  
Experimental Systems ◽  
Two Band Model ◽  
Pure Palladium

The thermal conductivity, electrical resistivity, and absolute thermoelectric power of pure palladium have been determined from 90 to 1300 K in two experimental systems of proven reliability. These properties are compared with the sparse available literature data, and show large deviations from them, particularly for the thermal conductivity at high temperatures. The results are also analyzed in terms of a simple two-band model, where one band contains the carriers, and the other acts as a trap into which phonons scatter the carriers. When the recent density of states values of Mueller et al. are used, the model predicts correctly the temperature variation of the electrical resistivity, and reasonably well its observed magnitude and the observed Wiedemann–Franz ratio. However, the model fails badly in respect to the absolute thermoelectric power, predicting values twice as large as the observed ones. Modifications to the model are suggested which may improve the fit between the predicted and observed values.

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 Power of the Liquid Sn—Te Alloy

1982 ◽  
Vol 37 (10) ◽  
pp. 1127-1131 ◽  
Author(s):  
D. H. Kurlat ◽  
M. Rosen
Keyword(s):  
Thermoelectric Power ◽  
Hard Sphere ◽  
Stoichiometric Composition ◽  
Band Model ◽  
Liquid Alloys ◽  
Sphere Approximation ◽  
The Difference ◽  
Predicted Values ◽  
Experimental Values ◽  
Two Band Model

The Seebeck coefficient (S) of Sni1-x- Tex liquid alloys was measured as a function of concentration and temperature. For 0 ≦ x <0.45 the behaviour is metallic; S values are small and negative, rising linearly with temperature. The predicted values of Ziman's theory when using the hard sphere approximation disagree with the experimental ones. The change in sign occurs for 0.45. For x = 0.5 (stoichiometric composition) the thermoelectric power decreases linearly with temperature. This fact is explained assuming a two-band model. For x ≧ 0.6 the liquid alloy becomes more semiconducting and presents a maximum in the isotherms of S for x = 0.65. For the excess tellurium concentration range we have calculated the difference EF - EV and γ/kB, assuming a S(1/T) law. The experimental values are compared with those of Dancy and Glazov.

The transport properties of the cubic alkaline earths Ca, Sr, and Ba

1978 ◽  
Vol 56 (1) ◽  
pp. 161-174 ◽  
Author(s):  
J. G. Cook ◽  
M. J. Laubitz
Keyword(s):  
Large Deviations ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Phonon Scattering ◽  
Thermal Resistivity ◽  
Elastic Electron ◽  
Phonon Drag ◽  
Alkaline Earths ◽  
Conductivity Function ◽  
Electron Phonon Scattering

The electrical resistivity (ρ), thermoelectric power(S), and thermal conductivity (κ) of two Sr samples and two Ba samples have been determined from 30 to 300 K. Large deviations from Matthiessen's rule (DMR) were observed. The estimated transport properties for ideally pure Sr and Ba indicate that these elements, like Ca, show large deviations from the Bloch–Gruneisen form for ρ(T) at all temperatures, large and positive diffusion thermopowers with a negative phonon-drag contribution, and large deviations from the Wiedemann–Franz relationship (DWFR). In these respects, they are much more like the transition metals than the monovalent metals.In the second, analytical, portion of the paper we study the DWFR in some detail. First, the effect of lattice conduction is estimated, and found to be large. Then, a function X(E) of the electron energy, closely related to the conventional conductivity function σ(E), is estimated from the ρ and S data now available for Ca, Sr, and Ba above 300 K, and used to compute S and the Lorenz function for elastic electron–phonon scattering below 300 K. Comparison with the experimental data indicates that the energy dependence of the electron parameters is responsible for the electronic DWFR, and effects the diffusion thermoelectric power. Such 'band effects' may also be seen in the thermal resistivity due to inelastic scattering in at least Sr. Regrettably, we are not able to explain the observed DMR.

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.

Electron Transport Properties of La1-xSrxTiO3 Under Hydrostatic Pressure

1997 ◽  
Vol 499 ◽  
Author(s):  
Charles C. Hays ◽  
Jianshi Zhou ◽  
John B. Goodenough ◽  
John T. Markert
Keyword(s):  
Electron Transport ◽  
Hydrostatic Pressure ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Thermoelectric Power ◽  
Room Temperature ◽  
Itinerant Electron ◽  
Electron Transport Properties ◽  
P Type

ABSTRACTThe temperature dependence of the resistance and thermoelectric power under hydrostatic pressure between 10 and 300 K are reported for two compositions, x = 0.044 and x = 0.05, of the narrowband system La1-xSrxTiO3. The application of hydrostatic pressure at room temperature induces a transition from a positive p-type to a negative n-type thermoelectric power for x = 0.044. This behavior is interpreted within a model of itinerant-electron antiferromagnetism in LaTiO3.

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