Atomic scale calculation of the free volume in Zr2Ni metallic glass

How to evaluate the free volume in metallic glasses is a long-standing question in the field of metallic glasses. In this paper, a new approach at the atomic level to calculate free volume has been developed and applied in the Zr2Ni metallic glass. The glass transition and volume change during the cooling of Zr2Ni metallic liquid were investigated by molecular dynamics (MD). The MD resultant glass transition temperature (Tg) is about 700 K, which is close to the experimental value of 662.8 K obtained from differential scanning calorimetry (DSC). According to our method, the free volume in Zr2Ni metallic glass was determined to be ∼4.1% at Tg, which is comparable with the experimental results reported in other metallic glasses. Moreover, the probability distribution of free volume in our case can be fitted well by that given by Turnbull and Cohen, confirming the rationality of our method.