Influence Of Phase Separation On Structure-property Relationships In The (GeSe2-3As2Se3)1-xPbSex Glass System

The physical properties of chalcogenide glasses in the (GeSe2-3As2Se3)1-xPbSex [GAP-Se] series (x=0-55 mol%) have been measured as a function of PbSe content and glass morphology. Measurements of density, microhardness, thermal properties (glass transition, stability and conductivity) and IR transmission spectra have been correlated with Pb content illustrating the impact of liquid-liquid phase separation (LLPS) on properties within this multicomponent chalcogenide glass system. The role of Pb as both a modifier and network participant is proposed as a structural interpretation of property variation across the series. Density, microhardness and thermal conductivity showed an increase with PbSe content whereas glass transition temperature (Tg) exhibits a minimum near the center of the immiscibility zone correlated to a decrease in glass stability when a Pb-rich matrix is present. The structural origin of the change in the properties is confirmed using Raman spectroscopy and transmission electron microscopy (TEM) which illustrate the different morphology of phase separation present and how it impacts property evolution