Strained rocksalt ScN: ab initio studies of electronic structure and lattice-dynamical properties

Generalized gradient approximation calculations are performed to determine electronic and lattice vibration properties of unstrained and strained rocksalt scandium nitride (ScN). In agreement with earlier studies, our results reveal that unstrained rocksalt ScN is an indirect gap semiconductor from the valence band at Gamma point to the conduction band at the X point. The effect of strain is found to have a large variation of energy band gaps and optical phonon frequencies. A large longitudinal and transverse optical phonon frequencies splitting is noted for the material of interest suggesting thus a remarkable dynamic ionicity of rocksalt ScN which varies significantly when ScN is strained. This can lead to engineering novel behaviors and holds promise for new technological applications.