Microstructural and magnetotransport studies of novel manganite–sebacic acid nanocomposites prepared at low temperature

Abstract

Abstract Novel La 2/3 Sr 1/3 MnO 3 :sebacic acid nanocomposites (LSMO–SA- X ) were prepared for different fraction additions ( X ) of sebacic acid (SA). The preparation of these nanocomposites was performed at low temperatures ( T ~130 °C) avoiding partial decomposition of the organic matrix. The microstructure of these LSMO–SA- X nanocomposites was studied by small angle X-ray scattering (SAXS) technique and both nanoparticles size and inter-particle distances were estimated. The magnetic, electrical and magnetotransport properties were also investigated. An enhancement in the low-field magnetoresistance (LFMR) for lower fractions of SA was obtained with respect to pure LSMO and higher fraction additions showed a decrease in the LFMR due to the higher separation distance between LSMO nanoparticles. The tunnel barrier thickness observed in these nanocomposites was correlated with the interparticle distance obtained by SAXS. The enhancement of magnetoresistance was attributed to the increase in the extrinsic disorder promoted by the SA addition and no enhancement due to intrinsic magnetoresistance of LSMO was evidenced.