Strain‐ and correlation‐induced half‐metallic ferromagnetism in orthorhombic BaFeO

Using first‐principles calculations, the electronic and magnetic properties of orthorhombic BaFeO (BFO) are investigated with the local spin density approximation (LSDA). The calculations reveal that at the optimized lattice volume, BFO has a lower energy in the ferromagnetic state as compared with the antiferromagnetic state. At the equilibrium volume, BFO shows metallic behavior, however, under a large tensile strain (), BFO shows half‐metallic behavior consistent with the integer magnetic moment of fu mainly caused by the and electrons of Fe. Including a Hubbard‐like contribution U (LSDA) on Fe d states induced half‐metallic behavior without external strain, which indicates that U can be used to tune the electronic structure of BFO. The magnetic moments remained robust against compressive and tensile strain. At large compressive (tensile) strain, the half‐metallicity of BFO is mainly destroyed by the Fe‐d (O‐p) electrons, in agreement with the noninteger value of the magnetic moments of BFO.