First-principles study of structure and properties of ω-Ti2Zr

The structural, elastic, electronic properties, and Debye temperature of omega-Ti2Zr under compression were investigated by the first-principles pseudopotential method based on density functional theory (DFT). The calculated structural parameters at zero pressure are inconsistent with experimental values. The elastic constants and their pressure dependence were obtained using the static finite strain technique. We derived the bulk modulus, Young's modulus and Poisson's ratio for omega-Ti2Zr. The Debye temperature was obtained by the average sound velocity, and compared with other Ti-Zr metals and alloys. The pressure dependence of electron distribution, as well as the s -> d electron transfer indicates that there is a omega -> beta phase transition in the high pressures regime. Finally, the heat capacity at the constant pressure and the linear thermal expansion coefficient as a function of temperature had been obtained. (c) 2013 Elsevier B.V. All rights reserved.