Prediction of solid-state amorphization in binary metal systems

A criterion is proposed for predicting the possibility of solid-state amorphization in the binary metal systems based on thermodynamic and kinetic considerations. A thermodynamic factor $\Delta F$ is defined to be the Gibbs free-energy difference between the initial multilayered films and the resultant amorphous phase, while a kinetic factor κ is defined to correlate not only with the atomic volume ratio but also with the melting point difference of the constituent metals. It turns out that if κ of a system is greater than a critical value of 0.6 together with a negative $\Delta F,$ solid-state amorphization is likely to take place in the system. The prediction is relevantly compatible with the experimental observations in the previously studied systems featuring either positive or negative heat of mixing as well as various values of atomic size difference.