STACKING-FAULT ENERGY OF THE NBCR2 LAVES PHASE

A total energy study has been performed on the NbCr2 Laves phase using first-principles electronic structure calculations based on the full- potential linear muffin-tin orbital method. For the two Laves phase st ructures, C15 and C14, cohesive energies and heats of formation were o btained. A method was developed to calculate the stacking fault energy , gamma, in C15 Laves phases, using only two quantities: the cohesive energy difference between C15 and C14 Laves phases, and the C15 lattic e constant. For C15 NbCr2, the calculated stacking fault energy is 90 mJ m(-2). The calculated result is in good agreement with an experimen tal result deduced from an extended dislocation node.