Synthesis, structure and electric studies for La0.7A0.3Mn0.96(InxAl(1−x))0.04O3; A=Ca and Sr perovskites

Two polycrystalline series of samples in the form La0.7A0.3Mn0.96(InxAl(1−x))0.04O3; A=Ca and Sr with (0.0⩽x⩽1.0) were synthesized using solid-state reaction. Rietveld analysis of the X-ray powder diffraction showed that, the Ca-series has an orthorhombic unit cell (space group Pnma) and the Sr-series is rhombohedral with (space group image). Structural parameters (refined lattice parameters, atom positions, bond distance, bond angles, valence sum, valence bond, bond lengths and bond angles) are reported and discussed as a function of In content for the two series. Resistivity measurements in zero field are carried out in the range 50–300 K for the Ca-series and in the range 300–400 K for the Sr-series. The obtained transition temperature Tρ at which the metal-semiconducting (MS) occurred, is discussed as a function of the compositional parameter x.