Crystal structure, electrical and magnetic properties of perovskites La0.5Sr0.5–xBaxCoO3 (x=0.0 and 0.25)

Abstract

Abstract The resistivity and magnetization of La 0.5 Sr 0.5– x Ba x CoO 3 ( x =0.0 and 0.25) system have been investigated. The resistivity of La 0.5 Sr 0.5– x Ba x CoO 3 has increased with Ba substitution. Magnetization curves of La 0.5 Sr 0.5– x Ba x CoO 3 ( x =0.0 and 0.25) have showed the large difference between field cooled M FC and zero field cooled M ZFC below T c . X-ray and neutron diffraction measurements have been also performed. The crystal structure of La 0.5 Sr 0.5 CoO 3 at room temperature is rhombohedrally distorted perovskite belonging to the space group R 3 c (No. 167) with the a − a − a − type tilt system. From the results of powder X-ray and neutron Rietveld analysis, it is demonstrated that the lattice parameter along the a-axis increases and the rhombohedral angle decreases with the Ba substitution. It is also shown that the octahedral tilting becomes smaller with the Ba substitution.