The effect of the rare earth A-site cation on the structure, morphology, physical properties, and application of perovskite AFeO3

In this study, the influence of the rare earth (RE) ions on the structure, morphology, magnetic behavior, dielectric properties, and application of AFeO3 perovskite was studied. The perovskite nanoparticles AFeO3 (A: La, Nd, and Sm) were synthesized using the citrate auto combustion method. The x-ray diffraction (XRD) confirmed that the perovskites have an orthorhombic structure. The samples' crystallite size ranges from 13 to 51 nm. The high -resolution transmission electron microscope (HRTEM) assures that the perovskites are synthesized in the nanoscale. AFeO3 multiferroics have antiferromagnetic behavior. The maximum magnetization (Mm) of the NdFeO3 is two times that of the SmFeO3, owing to the variation in the number of electrons in 4f. The dielectric constant values (epsilon/) are strongly influenced by the rare earth (RE) element ionic radii, with epsilon/ increasing as the RE ionic radii increase. The investigated perovskites have semiconductor like behavior. The toxic heavy metal Cr6+ is efficiently removed from water by AFeO3 (A: La, Nd, and Sm). The optimum pH value is observed to be 6, at which the maximum removal efficiencies are 88%, 84%, and 53% for NdFeO3, LaFeO3, and SmFeO3, respectively. The Langmuir and Freundlich isotherm models have been used to fit the experimental data.