Structural, magnetic and electrical properties of La1-xMgxFeO3 perovskites

Abstract

In this study, we synthesized La 1-x Mg x FeO 3 (x = 0.1, 0.2, and 0.3) powdered ceramics using sol − gel and sintering methods and their structure, magnetic and electrical properties have been investigated. All samples showed the Pbnm single phase, and structural analyses revealed a lattice distortion due to the addition of Mg that increases with increasing Mg content. Transmission electron microscopy revealed a decrease in particle size with increasing Mg content. The M − H hysteresis loops of the samples revealed that the samples with Mg substitution at the La site exhibits weak ferromagnetic behaviour, and the hysteresis loops increases with an increase in Mg content. The magnetisation increases as the Mg content is increased, which is might be related to the lower crystallite and particle sizes, as well as higher Fe 4+ /Fe 3+ ratio, as shown by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. Analysis of the electrical properties showed grain–grain boundary effect in the conduction mechanism and two relaxation mechanisms for low Mg contents (x ≤ 0.2), whereas only the grain effect and one relaxation mechanism were observed at higher Mg contents (x = 0.3). The temperature dependence of direct current conductivity obeys the Arrhenius law. The activation energy for the conduction mechanism decreased with an increase in the Mg content. These results contribute the important knowledge in promising the candidate electrode material in electrochemical application.