Instability of metastable solid solutions and the crystal to glass transition

Abstract

Crystal to glass transitions are simulated using molecular dynamics for an fcc binary random solid solution with varying atomic size ratios and concentrations. The transition occurs at a critical supersaturated solute concentration with a sufficiently large solute-solvent atomic size difference. Close to the amorphization, the shear elastic moduli become dramatically softened, accompanied by a Martensite-like structural change. Large strain fluctuations and small enthalpy and volume changes at the transition indicate that it is triggered by a mechanical instability reached in the metastable crystal.