First-principles calculation of stacking fault and twin boundary energies of Cr₂Nb

Abstract

The stacking fault and twin boundary energies of C15 Cr₂Nb are calculated by the first-principles local-density-functional approach. It is found that the intrinsic and extrinsic stacking fault energies are 116 and 94mJm⁻², respectively, and the twin boundary energy is 39mJm⁻². The lower extrinsic stacking fault energy is consistent with the fact that the C36 structure has a lower energy than the C14 structure. The calculated stacking fault energies at 0K are larger than the experimental values available in the literature. The equilibrium separations between Shockley partials based on the calculated elastic constants and stacking fault energies are also calculated.