First principles study of the electronic structure and magnetic properties of YFeO₃ oxide

Highlights: •The electronic structure of YFeO₃ is investigated using two first principles methods. •Calculation are performed using the GGA+U approximation. •Large Hubbard U values have to be used with care for this system. •The non colinear magnetic ground state is investigated. •The Spin-Orbit coupling has to be taken into account. - Abstract: The electronic structure and the magnetic properties of the multiferroic YFeO₃ perovskite are investigated using two different first principles methods based on the Density Functional Theory with the so-called Hubbard correction. The results obtained with both the Projector Augmented Wave method implemented into the Vienna Ab inito Simulation Package and the Full-potential Linearized Augmented Plane Wave method implemented into FLEUR are compared to investigate the impact of the use of large Hubbard parameter $U_{\mathrm{Fe}}$ values allowing to get a reasonable bandgap. It is shown that both approaches lead to very similar results as long as the majority spin Fe d states remain hybridized with the O p states; this being the case up to $U_{\mathrm{Fe}}$ values around 4 eV. For larger $U_{\mathrm{Fe}}$ values, when the majority spin Fe d states are strongly localized and weakly hybridized with the O states, different crystal field splittings behaviors are obtained leading us to the conclusion that such large $U_{\mathrm{Fe}}$ values should be use with care. In addition, including the Spin–Orbit coupling contribution, the weakly canted antiferromagnetic structure is investigated and it is shown that the canting decreases when $U_{\mathrm{Fe}}$ is increased. Finally, the comparison with a method, taking the self-energy of the electrons (the GW approximation) into account, shows that even using small $U_{\mathrm{Fe}}$ values results in large distortion of the occupied part of the band structure for this particular system.