Formation, phase analysis and properties of iridium containing perovskite

Perovskite-type oxide Sr 1.3La 0.7MnIrO 6 has been synthesized by solid-state reaction in air at various temperatures and structurally characterized by Rietveld refinement of powder X-ray diffraction data. The structure synthesized at 1473 K shows orthorhombic symmetry (S.G. Pnma), whereas that synthesized at 1623 K shows cubic symmetry (S.G. Pm 3 ¯ m). For the orthorhombic Sr 1.3La 0.7MnIrO 6, the structural phase transition from orthorhombic to cubic was observed near 773 K by the high temperature X-ray diffractometry. The electrical conductivity measurement shows semiconducting property above room temperature for both the phases. Breaking of slope in the temperature dependence of the conductivity brings evidence in support of the phase transition for orthorhombic Sr 1.3La 0.7MnIrO 6. At low temperature, the compounds show ferromagnetic behavior. Magnetic susceptibility data show that both the compounds obey Curie–Weiss law in the high temperature region with the effective magnetic moment consistent with an oxidation state of +3 for manganese and +4 for iridium.