Electronic structures and magnetic couplings of B-, C-, and N-doped BeO

The electronic structures and magnetic properties of B-, C-, and N-doped BeO supercells are investigated by means of ab initio calculations using density functional theory. The magnetic exchange constants of C-doped BeO at different doping levels are also calculated. A phenomenological band structure model based on p-d exchange-like p-p level repulsion between the dopants is raised forward to explain the magnetic ground states in B-, C-, and N-doped BeO systems. The evolution from antiferromagnetic phase to ferromagnetic phase of C-doped BeO supercell with C concentration decreasing can also be well explained using this model. The findings in this study provide a simple guide for the design of band structure for magnetic sp-electron semiconductor.