Structural transition and thermo-physical study of quaternary (Se80Te20)94-x Ge6Pb x (0 ≤ x ≤ 12) alloys

Abstract

ABSTRACT Pb chalcogenides have emerged as promising materials for advanced thermoelectric and optoelectronic devices. Structural transition and thermo-physical study of (Se80Te20)94-x Ge6Pb x (0 ≤ x ≤ 12) chalcogenide alloys are reported and discussed. Alloys under investigation have been prepared using melt-quench technique. Structural transformation has been analyzed using the X-ray diffraction and field emission scanning electron microscopy (FESEM). The X-ray diffraction pattern showed sharp peaks with x ≥ 8 at. wt.% signifying structural modification with higher doping of Pb content. The presence of characteristic peaks for Pb ≥ 8 at. wt.% indicates the formation of nano-chalcogenide alloys which is further confirmed by the FESEM. The chemical composition is checked by the energy dispersive spectroscopy. Variation of various thermo-physical properties of Se-Te-Ge alloys on addition of Pb content has been studied. Glass transition temperature is calculated using Tichy–Ticha and Lankhrost approaches and is found in concordance with experimental results. The chemical bond approach has been adopted to determine cohesive energy.