Journal of Physical Studies 4(2), 155–158 (2000) DOI: https://doi.org/10.30970/jps.04.155 THERMOPHYSICAL PROPERTIES OF LIQUID TERNARY CHALCOGENIDES

V. Sklyarchuk, Yu. Plevachuk

Laboratory of Liquid Metals and Semiconductors of the Faculty of Physics,
Ivan Franko National University of Lviv,
49 General Chuprynka Str., Lviv, UA-79044, Ukraine

Electroconductivity $σ(T)$ and thermo-e.m.f. $S(T)$ measurements were performed for ternary CuTlSe$_2$, CuAsSe$_2$, and TlAsSe$_2$ alloys in a wide temperature range (up to 1800 K) under ambient pressures of argon gas (up to 50 MPa). An exponential $σ(T)$ dependence observed for the above-listed systems points to a fact of a metal-nonmetal transition. Contrary to theoretical expectations parameters of an energy spectrum determined separately from $σ(T)$ and $S(T)$ measurements do not coincide. It was found that: 1) metallization temperature $T^S <T^σ$; 2) activation energy $E^σ(0)$ does not coincide with $E^S(0)$; 3) points of inflexion on ${\rm log}σ = f(T^{-1})$ curves reflect the activation energy increasing from $E^σ(0)_1$ to $E^σ(0)_2$ at constant $E^S(0)$. A metal-nonmetal high-temperature transition is interpreted in the frame of developed transformation mechanism of liquid semiconductors energy spectrum. This mechanism suggests an energy interval existence of charge transfer processes.

PACS number(s): 64.70.-p, 71.22.+i.

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