Occurrence of Hysteresis like behavior of resistance of $Sb_2 Te_3$ film in heating-cooling cycle

TL;DR

This study reports a hysteresis-like resistance behavior in Sb2Te3 films during heating and cooling cycles, influenced by film thickness, heating/cooling rates, and maximum temperature, explained by a thermal resistance model.

Contribution

It introduces a model considering thermal gradients and parallel resistances to explain hysteresis in Sb2Te3 films during thermal cycling.

Findings

Resistance loop area depends on film thickness, heating rate, maximum temperature, and cooling rate.

The resistance behavior is reproducible under identical thermal conditions.

Thermal gradients due to finite conductivity cause the hysteresis effect.

Abstract

Experimental observations of a peculiar behavior observed on heating and cooling ${\rm Sb_2Te_3}$ films at different heating and cooling rate are detailed. The film regained its original resistance, forming a closed loop, on the completion of the heating-cooling cycle which was reproducible for identical conditions of heating and cooling. The area enclosed by the loop was found to depend on (i) the thickness of the film, (ii) the heating rate, (iii) the maximum temperature to which film was heated and (iv) the cooling rate. The observations are explained on basis of model which considers the film to be a resultant of parallel resistances. The film's finite thermal conductivity gives rise to a temperature gradient along the thickness of the film, due to this and the temperature coefficient of resistance, the parallel combination of resistance changes with temperature. Difference in heating and cooling rates give different temperature gradient, which explains the observed hysteresis.