Electrical properties of chain and sheet mercury compounds

1985 ◽  
Vol 314 (1528) ◽  
pp. 115-124 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Electrical Properties ◽  
Fermi Surface ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Layered Compounds ◽  
Surface Model ◽  
Helium Temperature ◽  
Mercury Compounds ◽  
Chain Compounds

The electrical resistivity of the chain compounds Hg 3-δ AsF 6 and Hg 3-δ SbF 6 decreases with decreasing temperature. It is shown that the temperature dependence of the resistivity of Hg 3-δ SbF 6 depends on the rate that a sample is cooled from room temperature to liquid helium temperature. The electrical resistivity of the layered compounds Hg 3 TaF 6 and Hg 3 NbF 6 is metallic from 300 to 1.4 K. The induced torque, de Haas-van Alphen effect and resistivity of the chain compounds are related to the cylindrical Fermi surface model. Superconductivity of the compounds is discussed.

Frozen-in defects in bismuth in relation to its magnetoresistivity and thermoelectric power

1972 ◽  
Vol 329 (1579) ◽  
pp. 453-466 ◽  
Keyword(s):  
Experimental Study ◽  
Melting Point ◽  
Electrical Properties ◽  
Fermi Surface ◽  
Thermoelectric Power ◽  
Room Temperature ◽  
Surface Model ◽  
Anisotropy Ratio ◽  
Valence Band Edge ◽  
Low Field

An experimental study is presented of effects on the electrical properties of bismuth single crystals of quenching from about 4 K below the melting point (544 K ) into liquid nitrogen. Each of the twelve coefficients that describe the low field, magnetoresistivity tensor and the components of the thermoelectric power tensor has been compared in the annealed and quenched sample conditions at 77 K and at room temperature. Pronounced changes in the tensor coefficients at 77 K have been observed following quenching; the anisotropy ratio P 11 /p 33 zero resistivity in verts from 0.9446 before quenching to 1.030 after. Q uenching effects anneal out on heating to below room temperature. Results are analysed in terms of a two-band, multivalley Fermi surface model to obtain carrier densities and mobilities, the tilt angle of the electron ellipsoids and the Fermi energies and band overlap. Carrier densities at 77 K in both bands are 4.4 x 10 23 m -3 in the carefully annealed state. Quenching increases both the electron and hole densities, the former to 4.6 x 17 23 m -3 and the latter to 5.3 x 1023 m -3 ; the separation between the Fermi level and the valence band edge is increased markedly (27 %), as is the band overlap (13 %). The quenched-in defects show predominantly acceptor-like character. Carrier mobilities in the xy plane are reduced after quenching but those along the z axis are slightly increased.

Electrical Properties of Some Divalent Transition Cupferrone Complexes

1976 ◽  
Vol 31 (6) ◽  
pp. 675-676 ◽  
Author(s):  
H. F. Aly ◽  
F. M. Abdel-Kerim ◽  
H. H. Afifi
Keyword(s):  
Electrical Resistivity ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Uv Absorption ◽  
Cu And Zn

From the temperature dependence of the electrical resistivity of the divalent Mn, Co, Ni, Cu and Zn cupferrone complexes it is concluded that these compounds behave as semiconductors. It is also found that the charge transfere (CT) energy as calculated from the UV absorption CT bands is always larger than that drived from the electrical resistivity

Thermoelectric Properties of Zn4-xSb3 with x=0~0.5

2007 ◽  
Vol 124-126 ◽  
pp. 1019-1022 ◽  
Author(s):  
K.W. Jang ◽  
Il Ho Kim ◽  
Jung Il Lee ◽  
Good Sun Choi
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Temperature Dependence ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Hall Mobility ◽  
Room Temperature ◽  
Vacuum Melting ◽  
Increasing Temperature

Non-stoichiometric Zn4-xSb3 compounds with x=0~0.5 were prepared by vacuum melting at 1173K and annealing solidified ingots at 623K. Electrical resistivity and Seebeck coefficient at 450K increased from 1.8cm and 145K-1 for Zn4Sb3(x=0) to 56.2cm 350K-1 for Zn3.5Sb3(x=0.5) due to the decrease of the carrier concentration. Hall mobility and carrier concentration was 31.5cm2V-1s-1 and 1.32X1020cm-3 for Zn4Sb3 and 70cm2V-1s-1 and 2.80X1018cm-3 for Zn3.5Sb3. Electrical resistivity of Zn4-xSb3 with x=0~0.2 showed linearly increasing temperature dependence, whereas those of Zn4-xSb3 with x=0.3~0.5 above 450 K tended to decrease. Thermal conductivity of Zn4Sb3 was 8.5mWcm-1K-1 at room temperature and that of Zn4-xSb3 with x≥0.3 was around 11mWcm-1K-1. Maximum ZT of Zn4Sb3 was obtained around 1.3 at 600K. Zn4Sb3 with x=0.3~0.5 showed very small value of ZT=0.2~0.3.

High precision electrical resistivity measurements on potassium below 1 K

1982 ◽  
Vol 60 (5) ◽  
pp. 703-709 ◽  
Author(s):  
William P. Pratt Jr.
Keyword(s):  
Electrical Resistivity ◽  
Simple Model ◽  
Temperature Dependence ◽  
Temperature Variation ◽  
High Precision ◽  
Electron Scattering ◽  
Room Temperature ◽  
Temperature Treatment ◽  
Resistivity Measurements

New ultra-high precision (0.1 ppm) measurements of the resistivity of potassium down to 70 mK are discussed. Between 0.35 and 1.2 K. the resistivity has a T2 temperature dependence which is independent of the sample parameters and the room temperature treatment of the samples. This behavior is consistent with the predictions for simple electron–electron scattering, but such a simple model cannot adequately explain previous data. Below 0.35 K the data are anomalous in that the temperature variation is slower than T2.

Infrared Spectroscopy of Intersitial Oxygen in Silicon

1985 ◽  
Vol 59 ◽  
Author(s):  
Bernard Pajot ◽  
Bernard Cales
Keyword(s):  
Infrared Spectroscopy ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Liquid Helium ◽  
Isotope Shift ◽  
Room Temperature ◽  
Interstitial Oxygen ◽  
Helium Temperature ◽  
Temperature Spectrum ◽  
Weak Band

ABSTRACTA discussion of the isotope shift of the low temperature spectrum of the stretching mode of interstitial oxygen (Oi) in silicon introduces IR results showing the interaction of Oi with the silicon lattice. Evidence is given that the temperature dependence of a combination band observed at liquid helium temperature (LHT) at 1205.7 cm−1 is responsible for the room temperature (RT) band at 1227 cm−1 and that a weak band near 1013 cm−1 is an overtone of the 518 cm−1 band.

Temperature Dependence of Electroresistivity, Negative and Positive Magnetoresistivity of Graphite/Diamond Nanocomposites and Onion-Like Carbon

2001 ◽  
Vol 703 ◽  
Author(s):  
Anatoliy I. Romanenko ◽  
Olga B. Anikeeva ◽  
Alexander V. Okotrub ◽  
Vladimir L. Kuznetsov ◽  
Yuriy V. Butenko ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Carrier Concentration ◽  
Path Length ◽  
Vacuum Annealing ◽  
Localization Length ◽  
Free Path Length ◽  
Hopping Conduction ◽  
Structure Model ◽  
Helium Temperature

ABSTRACTHere we present the result of measurements of electrical resistivity and magnetoresistivity of graphite/diamond nanocomposites (GDNC) and onion-like carbon (OLC) prepared by vacuum annealing of nanodiamond (ND) at various fixed temperatures. GDNC contain particles with a diamond core covered by closed curved graphitic shells. The electrical resistivity of annealed ND is characteristic of systems with localized electrons and can be described in terms of variable hopping-length hopping conductivity (VHLHC). The magnetoresistivity of OLC is negative in the range of field 0<B<2 T, and is positive at B>2 T. The conduction carrier concentration for OLC samples was estimated in the framework of the theory of negative magnetoresistance in semiconductors in the hopping conduction region. The free path length for conducting electrons at liquid helium temperature was estimated from the data on positive magnetoresistivity. The localization length of current carriers was also estimated. The determined parameters are in agreement with proposed structure model of OLC constructed using HRTEM data.

Thermoelectric Properties of Tl-X-Te (X=Pb, Sn, Ge) Systems

2005 ◽  
Vol 886 ◽  
Author(s):  
Atsuko Kosuga ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Solid State ◽  
Electrical Properties ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Dimensionless Figure Of Merit

ABSTRACTPolycrystalline-sintered samples of Tl2GeTe3, Tl4SnTe3, and Tl4PbTe3 were prepared by a solid-state reaction. Their thermoelectric properties were evaluated at temperatures ranging from room temperature to ca. 700 K by using the measured electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ). Despite their poor electrical properties, the dimensionless figure of merit ZT of all the compounds was relatively high, i.e., 0.74 at 673 K for Tl4SnTe3, 0.71 at 673 K for Tl4PbTe3, 0.29 at 473 K for Tl2GeTe3, due to the very low lattice thermal conductivity of the compounds.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

Sign in / Sign up

Export Citation Format

Share Document