DFT simulations to clarify the molecular origin of magnetoelectric coupling in R3c materials based on Fe

Abstract

Multiferroic materials are characterized by the existence of ferroic properties coupled in a single crystalline phase and represent great promise for the development of spintronics devices. Another material reported with similar potential is FeTiO₃. Therefore, we perform an ab initio investigation using the DFT/B3LYP calculation level to investigate FeBO₃ (B = Ti, Ge, Zr, Sn and Hf) materials in the corundum ordered structure. The obtained results indicate that the investigated materials present a D_3d symmetry distortion of octahedral clusters, proved by modification of the t_2g and e_g energy levels of Fe atoms, as well as a half-metallic behavior observed in some of the investigated materials. In terms of multiferroism, the magnetoelectric coupling was investigated and, for the first time, theoretically evidenced for FeBO₃ materials, except for FeTiO₃. Anisotropies for ferroelectric and magnetic properties were noted along the unit cell and observed in tangent planes; hence, a perturbation in one of these properties automatically results in a response from another.