The influence of the ionic component of the electrical conductivity on thesemiconductor-metal transition in liquid Tl-Se alloys

Experimental investigations of electrical conductivity sigma (T) and thermo -e.m.f. S(T) were performed for liquid TI-Se alloys in the region of the st oichiometric compound Tl,Se in a wide temperature range (from 600 K to 1700 K). It was shown that the existence of an ionic component in the electrica l conductivity affects significantly the peculiarities of the metallization process of the liquid cells. A model explaining the unusual thermo-e.m.f. behavior, which forms a large deviation from the 'classical' dependence in a wide temperature range resulted from the effect of electron-hole compensa tion, has been proposed. The ionic contribution essentially changes the ele ctrical conductivity resulting in a deformation of the exponential curve si gma (T). (C) 2001 Elsevier Science B.V. All rights reserved.