New perovskite type oxides: NaATiMO6 (A = Ca or Sr; M = Nb or Ta) and their electrical properties

New oxides of the type, NaATiMO6 (M = Ca or Sr; M = Nb or Ta), have been prepared by the solid state reaction technique. Phase identification by powder X-ray diffraction (XRD) shows that NaCaTiMO6 have orthorhombic perovskite type structure (Space group, Pnma) and NaSrTiMO6 have cubic perovskite type structure (SG, Pm3m). The grain morphology observation by scanning electron microscope (SEM) shows well sintered grains. AC impedance spectral measurements in air, wet oxygen and dry oxygen atmosphere indicate that they are ionic conductors with conductivities of the order of 10− 4 S/cm at 750 °C.