LOW TEMPERATURE RESISTIVITY OF TRANSITION ELEMENTS: VANADIUM, NIOBIUM, AND HAFNIUM

1957 ◽  
Vol 35 (8) ◽  
pp. 892-900 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Electrical Resistance ◽  
Thermal Resistivity ◽  
Superconducting Transition ◽  
Transition Elements ◽  
Pure Niobium ◽  
Temperature Resistivity ◽  
The Ideal

Measurements of the thermal conductivity from 2° to 90 ° K. and electrical conductivity from 2° to 300 ° K. are reported for vanadium, niobium, and hafnium. Although the vanadium and hafnium are not as pure as we might wish, measurements on these metals and on niobium allow a tabulation of the "ideal" electrical resistivity clue to thermal scattering for these elements from 300 ° K. down to about 20 ° K. Ice-point values of the "ideal" electrical resistivity are 18.3 μΩ-cm. for vanadium, 13.5 μΩ-cm. for niobium, and 29.4 μΩ-cm. for hafnium. Values for the "ideal" thermal resistivity of vanadium and niobium are deduced from the experimental results although for vanadium and more particularly for hafnium, higher purity specimens are required before a very reliable study of "ideal" thermal resistivity can be made. For the highly ductile pure niobium, the superconducting transition temperature, as determined from electrical resistance, appears to be close to 9.2 ° K.

LOW TEMPERATURE RESISTIVITY OF THE TRANSITION ELEMENTS: COBALT, TUNGSTEN, AND RHENIUM

1957 ◽  
Vol 35 (5) ◽  
pp. 656-665 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Electrical Resistivity ◽  
Low Temperature ◽  
Thermal Resistance ◽  
High Purity ◽  
Thermal Resistivity ◽  
Superconducting Transition ◽  
Transition Elements ◽  
Experimental Values ◽  
Thermal Vibrations ◽  
Temperature Resistivity

Experimental values are reported for the electrical resistivity from 1.5° to 300° K. and for the thermal resistivity from 2° to 120° K. of high purity cobalt, tungsten, and rhenium. The temperature variation of the components of the electrical and of the thermal resistance due to scattering by thermal vibrations is deduced and the possible evidence for the importance of s–d transitions is discussed briefly. The temperature of the superconducting transition in samples of rhenium is found to be close to 1.70° K., the value reported by Hulm (1954).

LOW TEMPERATURE RESISTIVITY OF THE TRANSITION ELEMENTS: RUTHENIUM AND OSMIUM

1958 ◽  
Vol 36 (7) ◽  
pp. 875-883 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Electrical Resistance ◽  
Room Temperature ◽  
Inert Gas ◽  
Thermal Resistivity ◽  
Transition Elements ◽  
Arc Melting ◽  
Regular Shape ◽  
Gas Atmosphere ◽  
Experimental Values ◽  
Temperature Resistivity

Experimental values are reported for the electrical resistivity of ruthenium and osmium from 2 to 300 °K and for the thermal resistivity from 2 to 140° K. The samples were produced by arc-melting pressed pellets of metallic powder in an inert gas atmosphere. Two osmium samples and one ruthenium sample showed a satisfactorily low residual electrical resistance. By grinding these rods to a regular shape, absolute values of resistivity were obtained and the impurity and thermal components of resistivity derived; at room temperature (295 °K) we deduce that for ideally pure Os, [Formula: see text] and for ideally pure ruthenium [Formula: see text]. The temperature dependence of the resistivity was markedly different for another ruthenium sample but it seems likely that this was not representative of pure h.c.p. ruthenium.

Electrical and thermal resistivity of the transition elements at low temperatures

1959 ◽  
Vol 251 (995) ◽  
pp. 273-302 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Transport Equation ◽  
Low Temperatures ◽  
Group Iv ◽  
Standard Theory ◽  
Thermal Resistivity ◽  
Transition Elements ◽  
Thermal Vibrations ◽  
The Ideal

The results of measurements on 20 transition elements are reported giving values for the thermal resistivity, W , from 2 to about 140 °K and for electrical resistivity, p , from 2 to about 300 °K. Values of the ‘ideal’ resistivities, W i and p i { (due to scattering of the electrons by thermal vibrations), are deduced from these and tabulated for various temperatures. Comparisons are made with values for Cu, Ag, Au and Na and with the predictions of the ‘standard’ theory, i.e. solutions of the transport equation developed by Bloch, Grüneisen, Wilson, etc. Excepting Mn, p i follows a Bloch—Grüneisen function tolerably down to op5, although slight anomalies are shown by V, Cr, Fe, Co and Ni; at low temperatures behaviour is varied but below 10 °K in Mn, Fe, Co, Ni, Pd, Pt and perhaps in W and Nb, p i appears to vary nearly as T<super>2</super>. The parameter, piM 6 & (at 273 °K) has rather similar values for different members of each group, e.g. for Ti, Zr and Hf of group IV A. The ideal thermal resistivity, Wif can generally be approximated by the relation, WiIW ao = 2(Tld)2J 5(dlT), although for many elements, W i falls more rapidly than T 2 below010. Measurements on the relatively poor conductors, e.g. Ti, Zr and Hf, suggest the presence of an appreciable lattice conductivity, which affects the confidence with which values can be deduced for W i in these elements.

THERMAL AND ELECTRICAL CONDUCTIVITY OF RHODIUM, IRIDIUM, AND PLATINUM

1957 ◽  
Vol 35 (3) ◽  
pp. 248-257 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
High Purity ◽  
Low Temperatures ◽  
Rapid Rate ◽  
Transition Elements ◽  
Electron Collisions ◽  
Electrical Conductivities ◽  
Electrical Resistivities ◽  
The Ideal

Measurements are reported of the thermal and electrical conductivities of the transition elements Rh, Ir, Pt in a state of high purity; the rapid rate of decrease of the "ideal" thermal and electrical resistivities with temperature, particularly in Rh and Ir, suggests that s–d transitions are not a dominant resistive mechanism at low temperatures in these metals, in contrast to palladium, iron, and nickel, which were studied previously. The electrical resistivity of platinum is in general agreement with the earlier results of de Haas and de Boer (1934); the quadratic dependence on temperature observed below about 10° K. suggests that electron–electron collisions may well be an important factor in this metal.

Theoretical study of some electrical parameters of graphene

2016 ◽  
Vol 30 (29) ◽  
pp. 1650366
Author(s):  
D. K. Das ◽  
S. Roy ◽  
S. Sahoo
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Sample Size ◽  
Electrical Resistance ◽  
Theoretical Study ◽  
Lorenz Number ◽  
Electrical Parameters ◽  
Temperature Range

Graphene, due to its numerous unique properties, is addressed as miraculous material by Novoselov et al. [Nature 490 (2012) 192]. It has ultrahigh heat and thermal conductivity. Several researchers over the globe are working on electrical properties of graphene like electrical resistance, electrical conductivity etc. In this paper, we estimate electrical resistivity, electrical conductivity and Lorenz number for graphene within the temperature range from 300 K to 500 K. Variation of these parameters with respect to temperature and sample size is also reported.

The thermal and electrical conductivity of copper at low temperatures

1952 ◽  
Vol 211 (1104) ◽  
pp. 122-128 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Temperature Variation ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Small Deviation ◽  
Thermal Resistivity ◽  
Lorenz Number

Following previous work on sodium, the thermal and electrical conductivity of copper has been measured continuously between 90 and 2° K . The specimen was of spectrographic purity, and had been found to have a pronounced minimum in the electrical resistance at about 10° K . A similar, but smaller, anomaly was observed in the thermal resistivity with a corresponding small deviation from the Wiedemann-Franz law at the lowest temperatures. As in the case of sodium, marked disagreement with theory was found in the temperature variation both of the thermal conductivity and of the Lorenz number.

scholarly journals The theory of the transport phenomena in metals

1950 ◽  
Vol 203 (1072) ◽  
pp. 75-98 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Electric Power ◽  
Electrical Resistance ◽  
Free Electrons ◽  
Thermo Electric ◽  
Intermediate Temperature Range ◽  
Order Of Magnitude ◽  
Impure Metal ◽  
Ionic Lattice ◽  
The Ideal

Exact expressions, valid for all temperatures, are obtained in the form of infinite determinants for the electrical conductivity, the thermal conductivity and the thermo-electric power of a degenerate gas of quasi-free electrons interacting with the ionic lattice of a metal. It is shown that the values of the electrical and thermal conductivities, in general, exceed the values given by the approximate interpolation formulae due to Bloch (1930), Wilson (1937) and others, and, in particular, that the Grüneisen-Bloch formula for the ideal electrical resistance is appreciably in error in the region close to the Debye temperature. It is further shown that the residual and ideal resistances of an impure metal are not strictly additive in the region where the two are of the same order of magnitude. The behaviour of the thermal conductivity is shown to agree qualitatively with the discussion based on Wilson’s formula given by Makinson (1938); the numerical values of the thermal conductivity, however, are increased appreciably, particularly for an ideal metal at low temperatures. The thermo-electric power is also discussed, but no simple results can be given for the intermediate temperature range.

Designing Apparatus for Highly Precise Measurement of Electrical Conductivity and Seebeck Coefficient from 85 K to 1200 K

2013 ◽  
Vol 740 ◽  
pp. 426-432 ◽  
Author(s):  
Sopon Budngam ◽  
Aree Wichainchai ◽  
Saichol Pimmongkol ◽  
Udom Tipparach
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Electrical Resistance ◽  
Precise Measurement ◽  
Inert Gas ◽  
Vacuum System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas System

We describe the development of apparatus for measuring of electrical conductivity and Seebeck coefficient with high precision from 85 K to 1,200 K. Electrical resistance was measured by means of four-point probe method as a function of temperature. The temperature below 400 K was measured by using type T thermocouple in vacuum system was used and from 400 to 1,200 was measured by using Type S was applied for temperature between 400 and 1200 Kelvin in an inert gas system. With the dimensions of the specimen, the electrical resistivity (ρT) can be obtained in the unit of microohm-centimeter (μΩ-cm) and be written in polynomial, ρT=-0.3191+6.8×10-3T-6.0×10-7 T2+8.0×10-10T3. The electrical conductivity can be obtained by taking inversion of the electrical resistivity. Seebeck coefficient (αT ) can be calculated in microvolt per Kelvin as follows: αT=1.9653-1.49×10-2T+9.0×10-5T2-2.0×10-7T3+2.0×10-10T4-1.0×10-13T5+3.0×10-17T6 , when T is temperature in K. The Seebeck coefficient data was compared with X-ray diffraction (XRD) and X-ray fluorescence (XRF) of the specimen. The result showed that our developrd apparatus yields the same as standard method when copper with purity greater than 99 percent was employed.

Thermoelectric Performances of ZrNiSn/C60 Composite

2007 ◽  
Vol 280-283 ◽  
pp. 385-388 ◽  
Author(s):  
Xiang Yang Huang ◽  
Li Dong Chen ◽  
X. Shi ◽  
Min Zhou ◽  
Z. Xu
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seebeck Coefficient ◽  
Matrix Alloy ◽  
Nano Particles ◽  
Xrd Pattern ◽  
Plasma Sintering ◽  
Epma Analysis ◽  
Spark Plasma

The ZrNiSn/C60 thermoelectric composite was prepared by a spark plasma sintering (SPS)technique. The obtained sample was fully dense and homogeneous. Slices of the sample were characterized by electrical resistivity, Seebeck coefficient and thermal conductivity up to 850K. It was shown that the composite has a higher electrical conductivity, a lower Seebeck coefficient and a higher thermal conductivity than the ZrNiSn matrix alloy. XRD pattern and EPMA analysis of the composite revealed that the C60 nano particles reacted with ZrNiSn matrix to form ZrC inclusions.

scholarly journals Deviation from Matthiessen's Rule and Lattice Thermal Conductivity of Alloys

1959 ◽  
Vol 12 (2) ◽  
pp. 199 ◽  
Author(s):  
PG Klemens
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Lattice Thermal Conductivity ◽  
Pure Metal ◽  
Liquid Oxygen ◽  
Electronic Thermal Conductivity ◽  
The Difference ◽  
Matthiessen's Rule ◽  
Lattice Component ◽  
The Ideal

The purpose of this note is to point out that the difference in the ideal -electronic thermal conductivity between an alloy and a pure metal can be estimated from the corresponding difference in the ideal electrical resistivity, using the Wiedemann-Franz law. This allows the separation of the thermal conductivity into an electronic and a lattice component to be made with greater confidence, particularly at liquid oxygen temperatures.

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