Compositional dependence of temperature-activated electrical conductivity and resistance drift in GeTe–Sb₂Te₃ system

Temperature-activated conductivity was studied for several compositions from the GeTe–Sb 2 Te 3 pseudobinary system subjected to isothermal annealing at different temperatures. It is shown that while moving from GeTe-rich towards Sb 2 Te 3 -rich compositions, the response of the material to annealing changes substantially. In particular, the direction of resistivity changes inverses. Two possible explanations are proposed based on the gradual crystallisation of amorphous material at elevated temperature or its rejuvenation, which is a process opposed to structural relaxation leading to resistance drift. Based on the previously proposed approach, the temperature dependence of the Fermi level and its change after annealing is estimated, which shows a uniform behaviour all over the sample group.