Theoretical study of the structural phase transformation and elastic properties of the zirconium nitride under high pressure

The structural phase transition and elastic properties of zirconium nitride (ZrN) are investigated by using density functional theory (DFT) methods within the Perdew-Burke-Ernzerhof (PBE) form of generalized gradient approximation (GGA). Our calculated equilibrium structural parameters of ZrN are in good agreement with the available experimental data and other theoretical results. The obtained phase transition B1 -> B2 at ca. 210.41 GPa. This conclusion is in agreement with that of Hao et al., contrary to the theoretical calculation of Ojha et al. using a two-body interionic potential theory. We also found that the NiAs and WC phases are not stable in the whole pressure range considered. Especially, the elastic properties of B1-ZrN under high pressure are predicted. It is noted that the elastic constants, bulk moduli, shear moduli, compressional and shear wave velocities as well as Debye temperature of B1-ZrN increase monotonically with increasing pressure. By analyzing G/B, the brittle-ductile behavior of ZrN is assessed. In addition, polycrystalline elastic properties are also obtained successfully for a complete description of elastic properties. (C) 2012 Published by Elsevier Masson SAS.