Structural and optical properties of SmFe_0.8Mn_0.2O₃ nanocrystallites

The rare-earth metal oxides often manifest various unique properties such as quantum confinement drove band gap at the nano length scale due to larger surface/volume ratio. These properties have shown multiple applications in electronic, optical, and magnetic data storage devices. In this work, we have synthesized SmFe_0.8Mn_0.2O₃ (SFMO) ceramic powder with a solid-state reaction route. The structural analysis of the SFMO sample was determined by X-ray diffraction (XRD) and selected area electron diffraction (SAED), which suggest an orthorhombic crystal structure having Pbnm space group symmetry. SFMO nanoparticles of sizes ranging from 15 to 100 nm with an average particle size ≈ 20 nm have been observed by transmission electron microscopy (TEM). TEM micrographs clearly reveal the visualization of a polycrystalline pattern examined under SAED pattern supported by XRD data. The optical properties of SFMO have been studied with UV–vis spectroscopy. Subsequently, the sample's optical band gap was calculated to be 1.48 eV, which is smaller in contrast to the reported band gap (2.2 eV) of the parent SmFeO₃ compound. The experimental findings suggest that orthoferrite SFMO displays various distinct features compared to parent compounds SmFeO₃ and SmMnO₃. (author)