Composition-dependent properties and network structure of Ge-Se-Te chalcogenide glasses

Abstract

Ge12.5Se87.5-xTex (0≤x≤45) glasses were selected for elucidating the composition-dependent properties and network structure of Te-containing glasses. With increasing Te content (x), Vickers hardness (Hv) and glass transition temperature (Tg) initially increased and then decreased, showing a compositional threshold at x=27.5. It is found that the compositional trend of Hv and Tg is in good accordance with the structural evolution studied by Raman spectra. The results suggest that the introduction of Te leads to the evolution of the network connectivity and average bond strength of Ge12.5Se87.5-xTex glass structure, which imposes an opposite impact on the structural properties (Hv and Tg). This work provides a new insight to the structure-property correlation of Ge-Se-Te, which would facilitate the understanding of the structural role of Te in ChGs.