Thermal conductivity of alloys of the systems Sn-Pb and Sn-In in the solid and liquid states

Results are presented of the measurement of the thermal conductivity of alloys of the eutectic systems Sn-Pb and Sn-In in the solid and liquid phases from 100 to 600 °C by a steady-state method. The thermal conductivity of the investigated alloys depends linearly on the temperature. The contribution of the phonon and electron components to the thermal conductivity are estimated. It is concluded from the results that the presence of foreign atoms in the investigated alloys has no significant effect on the thermal conductivity, which is determined principally by the scattering of the electrons by the phonons.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 25–28, December, 1970.     

Thermal conductivity of selenium doped with indium and iodine in the solid and liquid states

We have measured the thermal conductivity in both the solid and liquid states for two amorphous samples. The first was selenium doped with indium and the second was selenium doped with iodine. The concentration of In and I in both samples was 50000 ppm in weight, which is equal to 3.33% for indium and 3.02% for iodine additives in atomic percent. The measurements were taken in the temperature range from 100 to 470°C and were carried out using the concentric cylindrical wall. It was found that the thermal conductivity of both samples is of the phonon type; its temperature dependence follows the relation K _ph T ^–1, and can be explained by the influence of thermal effects on the lattice structure.     

Thermal and electrical conductivity of CdSnAs<Subscript>2</Subscript> in solid and liquid states

The mechanisms of CdSnAs₂ heat and charge transfer in solid and liquid states were investigated. It was demonstrated that heat transfer in solid state is accomplished by phonons, electrons, diffusion, and the recombination of electron-hole pairs. A sharp increase in thermal and electrical conductivity up to the values characteristic of metals is observed upon melting. In contrast to metals, the electrical conductivity of CdSnAs₂ melt increases with temperature.     

Electrical conductivity and thermoelectric power of AgInSe2 in the solid and liquid states

The electrical conductivity and thermoelectric power of AgInSe₂ have been investigated as a function of temperature from 420°C to 950°C. Experimental data are analyzed in terms of a model developed for the density of states and electrical transport in solid amorphous semiconductors [1]. The activation energy calculated from electrical conductivity data is found to be 0.06 eV for the solid and 0.37 eV for the liquid phase. Moreover, the coefficient of the linear decrease of the energy gap with temperature was found to be 1.96×10^–4 eV/K.     

Phase diagram of the Bi-Sn system in the liquid and solid states

Results are given for the specific resistance, thermo-emf, and magnetic susceptibility in the range from room temperature up to 500 °C. The methods of measurement have previously been reported [1]. Each property is presented as a function of composition; the results are compared with ones for the system Bi-Cd. The temperature dependence of the three quantities is calculated for the alloy of eutectic composition.     

Thermal properties of liquid alloys of magnesium-lead system

The temperature variations of the density of liquid magnesium-lead alloys were measured by the gamma-method in the temperature range from the liquidus temperature to 950–1000 K for compositions of 19.11, 33.45, 52.46, and 83.06 at. % Pb. It is shown that within the estimated errors (0.25–0.30 %), the alloy density depends linearly on the temperature. Approximation dependences ρ(T) were obtained for every studied composition together with generalizing density-temperature and density-concentration dependences for the range of 0–100 at. % Pb. The work was financially supported by the Russian Foundation for Basic Research (Grant No. 06-08-00040).     

Plasma reflection in pure and doped bismuth-antimony alloys

Plasma reflection spectra in pure and doped Bi_1–xSb_x alloys, obtained in the 20–200 m wavelength range at nitrogen temperatures, are investigated and formulas by means of which the optical parameters of the materials are determined are given a foundation. The dependences of the plasma frequency on the antimony concentration and the degree of doping in the alloy are used for a quantitative confirmation of the validity of the proposed band models to describe the L zones and the scheme for reorganization of the energy spectrum of Bi_1–xSb_x alloys with the rise in antimony concentration x and in the temperature. An analysis showed that the Abrikosov model describes the experimental results better.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No.2, pp.5–20, February, 1976.In conclusion, we express our gratitude to A. D. Belaya and V. P. Gusakov for providing the doped bismuth—antimony specimens, to N. B. Brandt, Ya. G. Ponomarev, and O. N. Belousova for providing the apparatus to make the galvanomagnetic measurements and for discussing the results at different stages of the research, and also to V. M. Kostin for aid in the electronic computer computations.     

Thermal conductivity of liquid Ga

We present accurate values of the thermal conductivity of liquid Ga calculated from measurements of the Lorenz number and the electrical conductivity.     

Z-pinch dynamics under the combined breakdown in bismuth-antimony alloys

Time scans of the electric field in n-Bi_0.9Sb_0.1 samples are calculated under the impact ionization for various field orientations with respect to the crystal axes (the conditions of current given). The strong anisotropy of the pinch characteristics in the electron-hole plasma of such alloys is shown to be caused by the joint effect of the hole mobility anisotropy in the T-valley and the combined breakdown, the impact ionization being produced both by the external electric field and the Hall field. The magnitude of the latter is governed by the proper magnetic field of the current. The results explain the experimental data of Brandt et al. [1] who have observed the dynamical characteristics of the pinch in the above mentioned alloys to be strongly anisotropic.     

Positron trapping in the liquid and solid copper alloys

The peak counting rates of γ?γ angular correlation curves of positron annihilation (PCAC) in the liquid state fitted well to the straight line which had the same slope of the temperature dependence of the PCAC's attributed to the free annihilation in the solid state, for the Cu-8Ge and Cu-10.5Ge alloys and other copper solid solutions. The results of the positron trapping model fitting suggest the possibility that the positron in the liquid state repels the surrounding ions.     

Density of liquid and solid Mg-Pb alloys

Experimental data on the thermal properties of Mg-Pb alloys in solid and liquid states are generalized and analyzed. The temperature and composition dependences of molar volume and volumetric thermal expansion coefficient of the magnesium-lead system are constructed and discussed. The phase diagram of the system is refined.     

Thermal conductivity in dirty superconducting alloys in high field

This paper discusses the thermal conductivityK of a dirty type II superconductor in the mixed state, for fields close to the upper critical field (H _e2 orH _e3) where the electronic component is dominant and easily separated. To order |Δ|², the conductivity depends only on the space average 〈|Δ|²〉. Our formula is a generalisation of earlier results byMaki andAmbegaokar andGriffin for gapless superconductors. The slope\(\left( {\frac{{\partial K}}{{\partial H}}} \right)_{Hc2} \) is proportional to the slope of the magnetization curve\(\left( {\frac{{\partial K}}{{\partial H}}} \right)_{Hc2} \), the ratio of these two slopes being a universal function of temperature. These results are very different from the predictions of the “effective gap” model.     

Empty electronic states in solid and liquid nickel

The density of empty electronic states in solid and liquid nickel has been determined employing Auger electron appearance potential spectroscopy. The observed increase of the density-of-states at the Fermi level by a factor of 1.4 in the liquid is in good agreement with available resistivity data. An increase of d-holes from 0.6 to 1.0 upon fusion is also found and interpreted in terms of a reduced d-d-interaction in the liquid state.     

Shubnikov-de Haas effect and semimetal-semiconductor transition in bismuth-antimony alloys in high magnetic fields

Shubnikov-de Haas effect is observed in Bi and BiSb alloys (containing 0.1?4.4 at.% Sb) in pulsed high magnetic fields up to 420 kG. It is found that the amplitude of the quantum oscillation remarkably increases by mixing a small amount of Sb in Bi, and that the magnitude of the Hall electric field in BiSb alloy (0.1 at.% Sb) is much larger than that in pure Bi. These observations demonstrate the difference in the scattering mechanism of carriers between Bi and BiSb alloys. The magnetic field induced semimetal to semiconductor transition is observed in BiSb alloy with 4.4 at.% Sb. From the analysis of the Shubnikov-de Haas oscillation in BiSb, the field at which the semimetal to semiconductor transition will occur in Bi is estimated as about 1 MG for the field direction parallel to the binary axis.     

Thermal conductivity of liquid R507 refrigerant

Thermal conductivity of ozone-safe liquid refrigerant R507 was studied by the method of high-frequency thermal waves within the temperature range of 297.95 … 332.55 K and pressures from the saturation line up to 3.7 MPa. The estimated errors of temperature, pressure, and thermal conductivity measurements are 0.1 K, 3 kPa, and 1.5 %, correspondingly. Thermal conductivity of liquid R507 was calculated on the saturation line. Approximation dependences for thermal conductivity were derived for the whole range of studied temperatures and pressures and on the saturation line. The work was financially supported by the Russian Foundation for Basic Research (Grant No. 07-08-00295-a).