A topological basis for bulk glass formation

The shifting of bulk metallic glass compositions from their respective nearest eutectics is rationalized in terms of the variation of the glass transition temperature with composition near the eutectic. The composition dependence of the glass transition temperature is established by considering the competition between the internal degrees of freedom and the bond constraints between unlike atoms. The average bond constraint model requires as input only information that is readily available for any system of interest and provides estimates of: (i) the minimum solute concentration needed to form bulk metallic glass; (ii) the trend in the glass transition temperature as a function of composition; and (iii) the shift of the bulk metallic glass composition from the eutectic composition.