Ab initio Study of LuN (001) Surface

Structural and electronic properties of the lutetium nitride (001) surface have been studied with the density functional theory calculations and ab initio thermodynamics. A clean termination may be obtained in a wide range of the N chemical potential, whereas terminations with N vacancies and Lu adatoms may only be formed in Lu-rich conditions. The clean termination exhibits relatively small relaxations of interlayer distances near the surface, which leads to little changes in electronic properties compared to the bulk case. The presence of N vacancies and Lu adatoms may result in charge imbalance at the LuN surface. The findings presented in this work encourage further experimental search for novel rare earth nitride materials.