Possible metastable states in the Ni-W system predicted by<i>ab initio</i>calculations

Employing the Vienna ab initio simulation package, the total energies of six possible structures for the ${\mathrm{AB}}_{3}$ and ${A}_{3}B$ types were calculated as a function of their lattice constant(s). The calculation results predicted that the ${D0}_{19},$ ${L1}_{2},$ and ${D0}_{3}$ structures were relatively stable in the Ni-W system. Experimentally, a ${\mathrm{NiW}}_{3}$ hcp phase was indeed obtained in the ${\mathrm{Ni}}_{25}{\mathrm{W}}_{75}$ multilayered films upon thermal annealing and its lattice constants were in good agreement with the calculated ones.