Effect of lattice deformation on exchange coupling constants in Cr ₂O₃

We studied lattice deformation effect on exchange interaction in the corundum-type Cr₂O₃ theoretically. First-principles electronic structure calculations were performed to evaluate the total energy and exchange coupling constants of Cr₂O₃ under lattice deformation. We found that a few percent elastic deformation is expected via misfit strain and that the first- and second-nearest neighbor exchange coupling constants of Cr₂O₃ strongly depend on the lattice deformation. These results imply a possibility for improving the thermal stability of Cr₂O₃ based magnetoelectric devices by lattice deformation.