High Pressure Phase Transition and Superconductivity in Transition Metal nitride HfN and ZrN: an ab-initio Study

The high pressure structural investigations of HfN and ZrN have been studies using ab initio calculations. It is predicted that ZrN undergoes a structural phase transition from NaCl to ZB structure at around 90.17GPa whereas there is no phase transition for HfN. However at higher pressure (at 108.67GPa) HfN undergo a phase transition from ZB to WC structure. Apart from this, the ground state properties, elastic constants and superconducting transition temperature are calculated and compared with the available results.