Stability of amorphous structures with voids

Abstract

We incorporate the role of free volume in the density function of amorphous structure and study its effects on the stability of such structures. Density functional theory is used to explore this `free-volume model' of supercooled structures. Free-energy minimization is carried out using the void concentration as a variational parameter. A critical value of this concentration exists corresponding to the free-energy minima of the amorphous structure. An increase in the stability is observed due to the inclusion of voids in the density structure. This study is conducted for both weakly and highly localized amorphous structures. The free-volume concentration shows a power-law decrease with density for the weakly localized states and a linear decrease for the highly localized amorphous structures.