Variation in the dielectric and magnetic characteristics of multiferroic LuFeO3 as a result of cobalt substitution at Fe sites

Abstract

Due to its electrical, magnetic, and optical characteristics, LuFeO3 (LFO) has caught the scientific community's interest. In this study, the powders of LFO, LuFe0.95Co0.05O3, and LuFe0.90Co0.10O3 samples were prepared by using the well-known solid-state approach. The crystalline structure of the fabricated samples was examined by an X-ray diffractometer (XRD). It was found that the samples display secondary phases such as Lu2O3, Lutetium Tetraoxodiferrate, and Wustite. It was shown by scanning electron microscope (SEM) that particle size decreases with Co doping. X-ray photoelectron spectroscopy (XPS) determined oxidation states for Fe and Co. It was presented that Fe has a mixture of 2 + and + 3 valance states in the LFO sample. Although LuFe0.95Co0.05O3 has only the 3 + state, LuFe0.90Co0.10O3 sample has coexisting metallic and 3 + states. The conductivity and dielectric constant of the undoped LFO sample were higher than those of Co doped LFO samples. A decrease in both the dielectric constant and conductivity was associated with a lack of Fe2+ ions and lattice distortions. Furthermore, it was argued that several conduction models must be developed to explain the conduction process in the analyzed samples. Magnetic experiments using a vibrating sample magnetometer (VSM) revealed that Co doping raises Mr values. We discuss that this increase in Mr values could be related to i) variations in the inclined angles of Fe3+ moments and ii) the growth of magnetocrystalline anisotropy's energy.