Effect of substitutional doping on the Néel temperature of Cr2O3

First-principles calculations are used to explore the possibility of enhancing the Néel temperature T N of the magnetoelectric antiferromagnet Cr 2 O 3 by substitutional doping. We describe the electronic structure of transition metal (V, Ti, Mn, Fe, Co, and Ni) and anion (N and B) impurities and evaluate their effect on the exchange interaction. We find that, although transition-metal impurities and N are likely to reduce T N , substitution of O by B is likely to increase it. Both N and B impurities introduce impurity states mediating strong hybridization and magnetic interaction between the neighboring Cr ions. For N impurities, this leads to magnetic frustration, but in the case of B substitution, the stability of the ground antiferromagnetic state is enhanced.