Modification of the ferromagnetic properties of Fe-doped BaTiO3 polycrystalline ceramics by using Bi3+ doping

Abstract

We study the crystal structure and the magnetic properties of Ba1−xBixTi0.9Fe0.1O3 (0 ≤ x ≤ 0.12) ceramics prepared by using a conventional solid-state reaction. X-ray diffraction and Raman scattering spectroscopy measurements show that Bi 3+ substitution suppresses the formation of the hexagonal BaTiO3 phase and stabilizes the tetragonal BaTiO3 phase. The samples with x ≥ 0.08 demonstrate a single tetragonal BaTiO3 phase. Samples with x ≤ 0.1 show obvious magnetic orders at room temperature. The saturated magnetization, paramagnetic contribution and magnetic transition temperature are found to depend on the Bi doping concentration. Samples with 0.08 ≤ x ≤ 0.1 show a single tetragonal phase structure with a ferromagnetic order. These results indicate that the crystal structure and the ferromagnetic properties of Ba1−xBixTi0.9Fe0.1O3 (0 ≤ x ≤ 0.12) ceramics are intrinsic.

Toward an Enhanced Room-Temperature Photovoltaic Effect in Ferroelectric Bismuth and Iron Codoped BaTiO3

“…Although Ti-site specific substitution in BaTiO 3 by other non-d 0 elements (e.g., Fe, Mn, Co, etc.) lowers the band gap substantially, − it also strongly reduces the ferroelectricity, since they lead to the stabilization of paraelectric hexagonal BTO phase. , Similarly, a naive attempt to increase the conductivity of BTO through the incorporation of oxygen vacancies (each of which donates two electrons) also leads to the stabilization of the paraelectric BTO hexagonal phase in place of the ferroelectric tetragonal one at room temperature. , Interestingly, while only Fe-doped BTO (BaTi 0.9 Fe 0.1 O 3−δ ) stabilizes in an almost paraelectric hexagonal phase, the ferroelectric tetragonal phase can systematically be recovered back in Bi–Fe codoped BTO (Ba 1– x Bi x Ti 0.9 Fe 0.1 O 3−δ ) compounds. , …”