Мёссбауэровские исследования свойств твердых растворов xBiFeO-=SUB=-3-=/SUB=--(1-x)SrTiO-=SUB=-3-=/SUB=- (x=0.2/1.0; Delta x=0.1)

Abstract

Systematic Mössbauer studies of the magnetic structure and phase transition in the xBiFeO3- (1-x) SrTiO3 solid solution, where x varies from 0 to 0.8 with a step of 0.1, have been carried out. The multiferroic BiFeO3 was modified by the introduction of SrTiO3 perovskite, and solid solutions xBiFeO3- (1-x) SrTiO3 were obtained, which simultaneously possess ferrimagnetic and ferroelectric properties at room temperature. In the obtained xBiFeO3- (1-x) SrTiO3 systems, according to X-ray diffraction studies, there are no additional phases, while the Mössbauer data indicate the presence of mullinite (Bi2Fe4O9) with a SrTiO3 content in the solid solution from x = 1.0 to x = 0.8. The Mössbauer spectra of the xBiFe3- (1-x) SrTi3 system at room temperature show that with a decrease in the amount of BiFeO3 in the solid solution, the magnetic hyperfine field values ​​decrease and the absorption line widths increase due to the weakening of the magnetic exchange interaction. For compositions with x <0.5, the Mössbauer spectra indicate the paramagnetic state of the solid solution. Based on the dependence of the Zeeman line intensity on the BiFeO3 content in the xBiFeO3- (1-x) SrTiO3 solid solution, it was found that the transition to the paramagnetic state of the xBiFeO3- (1-x) SrTiO3 system at room temperature occurs near the value x = 0.4 (between x = 0.3 and x = 0.5).