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.

Effect of heavy rare‐earth substitution on physical properties of BiFeO3 thin films and their photocatalytic application

“…The energy difference between the bottom of the conduction band Fe-3d and the top of the valence band O-2p corresponds to the optical band-gap energy of BFO material. 40 As can be seen in the inset of Figure 6, the substitutions of RE ions for Bi 3+ in BFO show a significant steady decline in the band-gap energy of the BFO. For the heavy rare-earth substituted BFO thin films, the band-gap energies are between 1.18 and 1.65 eV.…”

“…According to Table 3, in comparison with previous works, the present study shows lower E g values. 39,40 The shape, size distribution, and structure type can play an important role in the bandgap of nanoparticles. The low band-gap energies (E g ) of the heavy rare-earth substituted BFO thin films show that these compounds can be suitable for use as visible light-responsive photocatalysts for the degradation of organic pollutants.…”

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.…”