Ab initio Calculation to Predict Possible Non-Equilibrium Solid Phases in an Immiscible Y-Nb System

抄録

In the equilibrium immiscible Y-Nb system, the total energies of the possible structures for Y₃Nb and YNb₃ non-equilibrium phases were calculated as a function of their lattice constant(s), under the frame work of the Vienna ab initio simulation package (VASP) and the calculated results predicted the relative stability of the Y₃Nb and YNb₃ phases crystallizing in four possible simple structures, i.e. A15, D0₁₉, L1₂ and L6₀ structures, respectively. Experimentally, a fcc Y₃Nb non-equilibrium phase was indeed obtained by ion beam mixing and its lattice constant determined by diffraction analysis was in agreement with the calculated value.