Temperature effects on the elastic constants, stacking fault energy and twinnability of Ni3Si and Ni3Ge: A first-principles study

Abstract

The volume versus temperature relations for Ni3Si and Ni3Ge are obtained by using the first principles calculations combined with the quasiharmonic approach. Based on the equilibrium volumes at temperature T, the temperature dependence of the elastic constants, generalized stacking fault energies and generalized planar fault energies of Ni3Si and Ni3Ge are investigated by first principles calculations. The elastic constants, antiphase boundary energies, complex stacking fault energies, superlattice intrinsic stacking fault energies and twinning energy decrease with increasing temperature. The twinnability of Ni3Si and Ni3Ge are examined using the twinnability criteria. It is found that their twinnability decrease with increasing temperature. Furthermore, Ni3Si has better twinnability than Ni3Ge at different temperatures.