The Physical Properties of Submicron and Nano-Grained La0.7Sr0.3MnO3 and Nd0.7Sr0.3MnO3 Synthesised by Sol–Gel and Solid-State Reaction Methods

La0.7Sr0.3MnO3 (LSMO) and Nd0.7Sr0.3MnO3 (NSMO) possess excellent colossal magnetoresistance (CMR). However, research work on the neodymium-based system is limited to date. A comparative study between LSMO NSMO prepared by sol–gel solid-state reaction methods was undertaken assess their structural, microstructural, magnetic, electrical, magneto-transport properties. X-ray diffraction structure refinement showed formation of a single-phase composition. Sol–gel-synthesised revealed be sample with single crystallite grains exhibited intriguing magnetic electrical transport behaviours. Magnetic characterisation highlighted that Curie temperature (TC) decreases grain size. Strong suppression metal–insulator transition (TMI) observed attributed magnetically disordered surface distortion MnO6 octahedra. The resistivity in metallic region fitted theoretical models, conduction mechanism could explained grain/domain boundary, electron–electron, electron–magnon scattering process. increase process ascribed morphology changes. Enhancement low-field (LFMR) nano-grained samples. obtained results show size its distribution, as well formation, strongly affect physical properties hole-doped manganites.