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)La3.67Sr0.33MnO3 + (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 T-EMI. 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. (C) 2014 Elsevier B.V. All rights reserved.