Phase stability and elastic moduli of Cr2Nb by first-principles calculations

The phase stability and elastic moduli of Cr2Nb are investigated by first-p rinciples calculations. Heats of formation are calculated and compared for the three Laves phases (C15, C14, and C36). It is found that the C15 phase is the ground-state structure with the lowest energy and the C36 phase is a n intermediate state between C15 and C14. These three phases, however, are very close in energy, indicating low stacking fault energies in this system . For the ground-state C15 phase, we calculate three elastic constants from which the shear and Young's moduli are obtained. It is found that these ca lculated moduli are smaller than the experimental values obtained from poly crystals. (C) 1998 Elsevier Science Ltd. All rights reserved.