Effect of Nitrogen and Fluorine Co-substitution on the Structure and Magnetic Properties of Cr2O3

First-principles density functional calculations were carried out to determine the structure as well as electronic and magnetic properties of N and F co-substituted Cr2O3. The formation of strong CrN bonds upon substitution of oxygen with nitrogen leads to large distortions in the local structure and changes in magnetic moments, which are partly compensated by co-substitution with fluorine. The effects of spin-orbit coupling are relatively weak, but its combination with local structural distortions gives rise to canting of spins and an overall magnetic moment in N, F co-substituted Cr2O3. Experimentally, we observe spin canting in N, F co-substituted Cr2O3 with considerable enhancement in the coercive field at low temperatures.