Prediction of Possible Metastable Alloy Phases in an Equilibrium Immiscible Y–Mo System by ab initio Calculation

In the equilibrium immiscible Y–Mo system, the total energies of the possible structures for YMo3 and Y3Mo metastable phases were calculated as a function of their lattice constants, by employing the Vienna ab initio simulation package, and the results suggested that the D019, L12, and L60 structures were three possible metastable states in the system. Experimentally, hcp and fcc YMo3 metastable phases were obtained in the Y–Mo multilayers driven far from equilibrium by ion irradiation. Moreover, the lattice constants determined by diffraction analysis were in agreement with the predicted values.