Phase stability and electronic structure of the HfAl3 compound -: art. no. 205102

First-principles total-energy calculations have addressed the problems of (i) bonding, cohesion, and phase stability and (ii) the role of antiphase boundaries in determining the structural and electronic properties of the HfAl3 compound. In this compound, the tetragonal D0(23) structure is stabilized relative to cubic Ll(2) by a tetragonal distortion and atomic relaxations. Location of the Fermi level in a pseudogap in the density-of-states distribution rationalizes the calculated structural stabilities. The energetic results are also discussed in the framework of the axial-next-nearest-neighbor Ising model.