First-principles study of elastic and structural properties of Zr<Subscript>3</Subscript>Al<Subscript>3</Subscript>C<Subscript>5</Subscript>

The elastic and structural properties of Zr<Subscript>3</Subscript>Al<Subscript>3</Subscript>C<Subscript>5</Subscri pt> have been investigated by means of first-principles pseudopotential total energy method. The lattice constants and internal parameters of atoms are in agreement with the available results. The pressure dependence with the elastic constants indicates Zr<Subscript>3</Subscript>Al<Subscript>3</Subscript>C<Subscript>5</Subscri pt> possesses mechanical stability in the pressure range 0–40 GPa. The calculated Cauchy pressure and ratio of bulk modulus to shear modulus reveal that Zr<Subscript>3</Subscript>Al<Subscript>3</Subscript>C<Subscript>5</Subscri pt> is intrinsically brittle in nature at zero pressure. Moreover, we derived the bulk and shear moduli, Young’s moduli and Poisson’s ratio from elastic constants for Zr<Subscript>3</Subscript>Al<Subscript>3</Subscript>C<Subscript>5</Subscri pt>. The variations of Debye temperature with pressure were estimated from the pressure dependence with average sound velocity. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012