Electronic structure and phase stability of three series of B2 Ti-transition-metal compounds

Abstract

Self-consistent electronic structure calculations have been performed for the 12 B2 TiM compounds (M=Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt, Au) using the linear muffin-tin orbital (LMTO) method. The calculated lattice constants and bulk moduli are in good agreement with measurements. An analysis of the possible correlations between the instability of the B2 structure and the electronic structures of the 12 TiM compounds has been carried out. The sequence of the B2 phase instabilities and the cubic to orthorhombic (or monoclinic) to orthorhombic (or monoclinic) to tetragonal tendency in the three TiM series have been discussed in terms of a band filling effect. The possible driving mechanisms of the structural phase transitions in the TiM series have been analysed based on the results of generalized susceptibility X0(q) calculations.