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 bo undaries in determining the structural and electronic properties of the HfA l3 compound. In this compound, the tetragonal D0(23) structure is stabilize d 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 distr ibution rationalizes the calculated structural stabilities. The energetic r esults are also discussed in the framework of the axial-next-nearest-neighb or Ising model.