First-principles studies of the structural, elastic, electronic and thermal properties of γ′-Ni3Ti

The structural, elastic and electronic properties of ordered face-centered cubic (L1(2)) gamma'-Ni3Ti were studied using the projector-augmented-wave (PAW) method within the generalized gradient approximation (GGA). The fact that the elastic constants meet the requirements of mechanical stability for a cubic crystal indicates that gamma'-Ni3Ti is mechanically stable at 0 K. The bulk modulus, shear modulus, Young's modulus and Poisson's ratio are estimated from the calculated elastic constants of single crystal. The ratio of the bulk modulus to shear modulus (B/G) is 2.00 and the material is ductile. Through the quasi-harmonic Debye model, the pressure and temperature dependences of the linear expansion coefficient, bulk modulus, the Debye temperature and heat capacity have been investigated for the first time. (C) 2012 Elsevier B.V. All rights reserved.