First Principles Investigation of Electronic Property and High Pressure Phase Stability of SmN

An investigation of electronic property and high pressure phase stability of SmN has been conducted using first principles calculations based on density functional theory. The electronic properties of SmN show a striking feature of a half metal, the majority-spin electrons are metallic and the minority-spin electrons are semiconducting. It was found that SmN undergoes a pressure-induced phase transition from NaCl-type (B1) to CsCl-type structure (B2) at 117 GPa. The elastic constants of SmN satisfy Born conditions at ambient pressure, indicating that B1 phase of SmN is mechanically stable at 0 GPa. The result of phonon spectra shows that B1 structure is dynamically stable at ambient pressure, which agrees with the conclusion derived from the elastic constants.