Chemical aspects of glass formation in telluride systems

The compositional dependence of the electrical activation energy, the optical absorption and the glass transition temperature in typical binary, pseudo-binary and ternary glass forming telluride systems has been measured in an effort to correlate chemical binding with physical properties. A modification of the valency satisfaction model to include chemical ordering effects is required to account for the property singularities observed in the GeTe system at the composition GeTe₂. The ordering effects in Te-based alloys containing Ge are further verified by an endothermic disordering reaction in these liquids peaking between 400–475°C depending on composition.