Enhancement of the magnetoelectric effect in doped BaTiO3 nanoparticles

Abstract

Experimentally the polarization P and the magnetization M of BaTiO3 (BTO) nanoparticles are altered under doping with transition metals as Fe‐ions. Using a modified spin model for the magnetic and the ferroelectric part as well as the magnetoelectric coupling we have calculated the dependence of M and P on the Fe‐doping content in BTO nanoparticles. The ferroelectric and ferromagnetic phase transition temperatures, Tcfe and Tcfm, are likewise shifted due to doping. Owing to surface effects the influence of doping could be stronger compared to the bulk behavior. Whereas M and Tcfm increase with increasing Fe‐ion concentration, P and Tcfe decrease if the dopant concentration is enhanced.

Dielectric Properties in Transition Metal and Rare‐Earth‐Doped Multiferroic BaTiO3 Nanoparticles

“…The effect of Fe doping in bulk BTO on structural, optical, and electronic properties is studied by density functional theory [20] and on the polarization using the defective dipole model in Monte-Carlo simulations. [21] In previous studies, [22,23] we have investigated the origin of ferromagnetism in pure and transition metal-doped BTO NPs. The aim of this study is using different microscopic models to study the dielectric properties of Fe-and Er-doped BTO-bulk and NPs-to clarify the discrepancies in the literature.…”