Structural, morphological, and functional characterization of LaMnO3 nanoparticles synthesized via the reverse micelle method

LaMnO 3 (LMO) nanoparticles were synthesized using the reverse micelle route and thoroughly characterized to determine their structural, morphological, optical, electrical, and magnetic properties. The single-phase formation of a cubic deformed perovskite structure with good crystallinity was confirmed by X-ray diffraction (XRD) and Rietveld refinement. Irregularly shaped nanoparticle agglomeration with a porous morphology was observed by scanning electron microscopy (SEM), and a homogeneous elemental distribution and phase purity were confirmed through energy-dispersive X-ray spectroscopy (EDS). Fourier-transform infrared (FTIR) spectroscopy complemented the characteristic Mn–O vibrational modes, allowing the stabilization of the well-defined MnO 6 octahedra. UV–visible spectroscopy indicated a direct optical bandgap of approximately 1.96 eV, suggesting its potential for use in visible-light-driven electronics. Electrical resistivity measurements exhibited thermally activated behavior with an activation energy of 0.21 eV, which is compatible with small polaron hopping in perovskite oxide semiconductors. Magnetic measurements at room temperature revealed that the size-induced surface effects and oxygen vacancies caused weak ferromagnetism. • LaMnO 3 nanoparticles were prepared successfully by a reverse micelle route with a stringent crystallite size and phase purity control. • Structural examination demonstrated a distorted cubic perovskite structure of high crystallinity and uniform elemental distribution. • Optical investigations showed a direct band gap of ~1.96 eV with potential for visible light powered optoelectronic devices. • Electric resistivity also exhibited a thermally stimulated conduction process after small polaron hopping with an activation energy of 0.21 eV. • Weak ferromagnetism at room temperature was demonstrated, resulting from surface spin disorder and oxygen deficiency, and therefore these nanoparticles are promising for spintronic devices.