A DFT investigation on magnetoelectric coupling in PbBO3 (B = V, Cr, Mn, Co, and Cu) materials: The influence on multiferroic properties

The multiferroism is a very intriguing property discovered more than seventy years ago and largely investigated mainly after 2003 due to a strong magnetoelectric coupling observed in some materials. However, even this phenomenon has been known for so long, until now its origin at the molecular level has not been clarified for many materials yet. Thus, in this work is proposed a systematic DFT study using PbBO3 (B = V, Cr, Mn, Co, and Cu) materials, which materials show good potential as a material for multiferroic or spintronic devices. The structural properties indicate that chemical modification on B magnetic sites has not a big influence on unit cell symmetry; in addition, the investigation of energetic stability indicates that such materials are highly stable under room conditions and high pressures. As well as, the electronic properties show that all materials present metallic band gap or half-metallic ferromagnetism. In terms of magnetic property, the theoretical results show a ferromagnetic ordering for PbMnO3 and PbCuO3, while PbVO3, PbCrO3, and PbCoO3 are antiferromagnetic materials with weak-ferromagnetism. In both cases, the magnetic resultant is oriented along [1 1 1] direction. In turn, all materials presented good ferroelectric properties with anisotropic features and more pronounced along the x-direction. Once those magnetic and ferroelectric properties are tangents, such coupling is possible because of one perturbation in one property results on the immediate answer of the other property. Thus, the fact of cationic magnetic sites (magnetic property) was displaced from the center of the octahedral site (ferroelectric property) is molecular origin for magnetoelectric coupling on proposed materials.