Elastic properties and stacking fault energies of Cr2Ta

The elastic moduli, stacking fault and twin boundary energies of C15 Cr2Ta are calculated by first-principles local-density-functional approach. Simil arly to the case of Cr2Nb, Cr2Ta is characterized by a low twin boundary en ergy (33 mJ/m(2)). On the other hand, the intrinsic and extrinsic stacking fault energies are found to be 88 and 83 mJ/m(2), respectively. Using the r esults of elastic constants and stacking fault energies, we predict the equ ilibrium separation between Shockley partials. The results of Cr2Ta are com pared with those of Cr2Nb. (C) 1999 Elsevier Science Ltd. All rights reserv ed.