Correlation between thermo-mechanical properties and network structure in Pb-As2S3 quasibinar chalcogenides

Abstract

This paper is concerned with establishing the correlation between some mechanical, thermal and structural properties of Pbx(As2S3)100-x glassy samples, x = 1, 2 and 3 at.%. Measurements of mechanical parameters were performed using a Fischerscope HM2000 S nanoindentation device. The obtained results indicated decrease in the microhardness as a function of the doping element content, as well as a pronounced normal indentation size effect (ISE) phenomenon in the range of lower indentation loads. In order to describe the microhardness data in the ISE regime and to determine the load independent microhardness value, the MPRS model was used. The increase in glass transition temperature with heating rate observed in DSC curves was described according to the Lasocka equation. The activation energy of softening process was evaluated using the Kissinger’s method. The KAS model was applied to estimate the activation energy as a function of the conversion rate. Raman measurements were employed to investigate structural changes due to Pb doping.

Keywords

• chalcogenides
• microhardness
• indentation size effect
• glass softening
• raman spectroscopy