Structural and magneto-transport properties of (1 − x)La0.67Sr0.33MnO3 (LSMO) + (x)BaTiO3 (BTO) composites

Influence of BTO phase on structural and electric properties of LSMO phase has been investigated by synthesizing a manganite matrix-based composite series (1 − x)La0.67Sr0.33MnO3 + (x)BaTiO3 with x = 0.0, 0.05, 0.10, 0.15, 0.20, and 0.25 (abbreviated as LSMO-BTO) by solid-state reaction method. Rietveld refined X-ray diffraction (XRD) data infers that manganite LSMO compound possess a rhombohedrally-distorted structure (space group R3c), while to that BTO compound crystallizes in tetragonal structure (space group P4mm). The structural parameters and the reliability factors for the LSMO-BTO composite ceramics were successfully determined by the Rietveld refinement. The resistivity measurements infer that the metal-insulator transition temperature was shifted towards lower temperature as well as resistivity increases with increasing BTO content in LSMO-BTO composites. Measurement of resistivity of these samples shows more prominent extrinsic metal insulator (EMI) transition at temperature TEMI. At H = 8 T, the magnetoresistance is enhanced in the wide temperature ranges due to introduction of BaTiO3 content in La0.67Sr0.33MnO3 which could be explained by enhanced spin polarized tunneling.