Electronic and magneto-optical properties of rare-earth orthoferrites RFeO₃ (R = Y, Sm, Eu, Gd and Lu)

Orthorhombic rare-earth orthoferrites are studied using density-functional theory. The electronic, optical and magneto-optical properties are investigated in both ferromagnetic (FM) and anti-ferromagnetic (AFM) phases. Our calculations show that the antiferromagnetic phase is energetically favorable. The calculated complex Kerr rotation of YFeO₃ is in good agreement with the experimental data. Our calculations yield a value of the magneto-optical Kerr angle between -0.4 to 0.4 degrees. To see the resemblance between the complex Kerr rotation and complex optical conductivity, we also have calculated the diagonal and the off-diagonal components of the optical-conductivity tensor.