Estudo das propriedades da perovskita mista de ferro e manganês

Abstract

The continued and growing demand for high-performance, more versatile and miniaturized electronic devices has increased interest in the study and development of new materials. In that sense ceramic with magnetic properties has emerged as a field of great interest and new studies are developed every day. In this work the mixed perovskite of iron and manganese (MnFeO3) was synthesized by the combustion method, sintered at different temperatures (500°C, 750°C and 900°C) and characterized by X-ray diffraction associated with the Rietveld method (DRX-Rietveld ) and X-Ray Fluorescence (FRX), while its magnetic properties were studied by Vibrating Sample Magnometry (VSM) and Electronic Paramagnetic Resonance (EPR).Analysis of the DRX-Rietiveld spectra showed that in the sample sintered at 500 °, formation of oxide mixtures occurred while only 64% of the material was transformed into FeMnO3 of cubic structure, whereas in the sintered samples at 750 and 900 ° the formation almost that absolute of FeMnO3 with a small excess of iron oxide III, attributed to an experimental error. The X-ray fluorescence confirms the XRD information, showing the percentages of oxides formed, proving the stoichiometry of the reaction.Paramagnetism was investigated by EPR analysis and showed a wide signal in the region of 0.3 teslas, the calculation of the factor g for the three samples shows values close to two, being close to the theoretical value for a free electron confirming the paramagnetism. The magnetization curve as a function of the applied field (M x H) obtained by the VSM technique shows values of magnetization of material considered soft, including the sample sintered at 750 ° C shows results for a superparamagnetic material.