Structural and electronic properties of the martensitic alloys TiNi, TiPd, and TiPt

The electronic and structural properties for TiNi, TiPd, and TiPt are studied using first-principles total energy calculations. For each alloy, the structural parameters for a few structural phases are found from energy and force calculations. In each case, we found that the ground state martensitic phase ${(B19/B19\mathrm{}}^{\prime })$ is indeed lower in energy than the high temperature $B2\mathrm{}$ phase. In all three alloys, the lowering in energy of the ${B19/B19\mathrm{}}^{\prime }$ structure is associated with the electronic properties such as lowering of the density of states at the Fermi level at the Ti site, and the broadening of the transition-metal $d$ bands in the ${B19/B19\mathrm{}}^{\prime }$ phase compared with the $B2\mathrm{}$ phase.