Electronic structures of MnP-based crystals: LaMnOP, BaMn2P2, and KMnP

Electronic and magnetic structures of MnP-based compounds, LaMnOP, BaMn2P2, KMnP and MnP, are calculated by density functional theory at the generalized gradient approximation (GGA) + U level. It reveals that the anti-ferromagnetic (AFM) configuration between the adjacent MnP layers is more stable by ∼80 meV than the ferromagnetic (FM) configuration for BaMn2P2, while LaMnOP and KMnP have almost no spin interaction between the MnP layers. This difference is explained by the shorter inter-layer spacing in BaMn2P2. The defect formation energies calculated for LaMnOP suggest that oxygen substitution at the P sites and P vacancies are the most easily formed point defects and explain the observed n-type conduction in nominally undoped polycrystalline samples.