Biplab Sanyal: Evolution of electronic and magnetic structures in spinel C0Cr2O4 with Fe doping

In this talk, I will present a systematic study of the effects of Fe doping on the electronic and magnetic structures of spinel CoCr₂O₄ by ab initio density functional theory and atomistic spin dynamics calculations. The calculated magnetic structure with a q-vector of (0.67, 0.67,0.0) is in excellent agreement with experimental findings for pristine CoCr₂O₄. I will show that the non-collinear spin structure with a non-zero q-vector in the spinel structure is driven towards collinearity with Fe doping by a complex interplay between interatomic exchange interactions. In the inverse spinel structure with 100 % Fe doping, a collinear antiferromagnetic order develops along with a half metallic electronic structure, which evolves due to the chemical disorder between Fe and Co in the B sites .