The Effect of Annealing Temperature on Structural, Electrical and Magnetic Properties of La0.9Sr0.1MnO3 Manganite

In this study، a manganite sample with a nominal formula of La0. 9Sr0. 1MnO3 was prepared by the microwave assisted sol-gel method and annealing at various temperatures. The structural and magnetic properties of the samples were investigated by XRD، FESEM and AC susceptometer، respectively. XRD analysis showed that the samples are a nearly single phase. FESEM micrographs showed that by increasing the annealing temperature from 600 to 1200 oC the size of particles increased from about 50 nm to micrometer. It was also found that the width of paramagnetic-ferromagnetic transition temperature and the magnitude of the susceptibility of samples decrease and increase by increasing annealing temperature، respectively. Also، in the resistivity curves of the micrometer particle sized samples، intergarnular and intragranular phase transition peaks were observed، while the intragranular peak was not seen in the nanometer particle sized sample. These behaviors are related to the surface effects.