The Properties of xBiFeO3–(1 – x)SrTiO3 (x = 0.2–1.0; Δx = 0.1) Solid Solutions: Mössbauer Studies

Abstract

The magnetic structure and phase transition in xBiFeO3–(1 – x)SrTiO3 solid solutions, where x is from 0.2 to 1.0 with a step of 0.1, are studied systematically with Mossbauer spectroscopy. The multiferroic BiFeO3 was modified via incorporation of a perovskite SrTiO3, and xBiFeO3–(1 – x)SrTiO3 solid solutions that possess both ferrimagnetic and ferroelectric properties at room temperature were prepared. X-ray diffraction data indicate that there are no any additional phases in the xBiFeO3–(1 – x)SrTiO3 systems, whereas Mossbauer data show that there is a mullinite (Bi2Fe4O9), when amount x of SrTiO3 in the solid solution is from 1.0 to 0.8. The Mossbauer spectra of the xBiFeO3–(1 – x)SrTiO3 system at room temperature show that when amount of BiFeO3 in the solid solution decreases, the magnetic hyperfine field values decrease as well and the widths of absorption line increase due to the weakening of the magnetic exchange interaction. The Mossbauer spectra of the systems with x < 0.5 indicate that the solid solution is paramagnetic. A relationship between the intensity of Zeeman lines and an amount of BiFeO3 in BiFeO3–(1 – x)SrTiO3 solid solution showed that the transition of this system to the paramagnetic state proceeded at room temperature, when x value was 0.4 (between x = 0.3 and 0.5).