Structural, electrical, magnetic and microstructural behavior of theLa0.7Sr0.3−xHgxMnO3 (0≤x≤0.3) system

Abstract

We report a detailed investigation on the polycrystalline samples of the colossal magnetoresistancesystem La0.7Sr0.3−xHgxMnO3 (0≤x≤0.3). The emphasis is put on identifying the role of Hg in the perovskite matrix. We have usedthe neutron diffraction technique for structural analysis. The issues pertaining tocomposition-dependent variations in parameters like average ionic radii, tolerance factor,variance, bond length, bond angle, lattice parameters and cationic vacancies have beenaddressed. The low temperature resistivity measurement and subsequent curve fitting areused to explore the contributions from various disorders and interactions. The samples withx = 0.3 composition showed distinct electrical behavior and magnetoresistance up to 46% aroundT = 198 K. The low temperature neutron diffraction data revealed ferromagnetic character of thesamples. All the samples displayed similar microstructures. The variations in the electricaland magnetic properties are attributed to origination from cationic disorders.