Effect of Sr-doping on the structural and electrical properties of gadolinium manganite oxide

The crystal structure and electrical conductivity of the perovskite oxide system Gd1-xSrxMnO3±δ (x = 0–0.5) were investigated. The effect of the level of Sr-doping on these properties was examined. An orthorhombic GdFeO3-type structure (space group Pbnm) was found for all oxides. The room temperature lattice parameters were determined from the XRD data. A large distortion of the unit cell was observed in the case of the undoped compound. The distortion was gradually reduced with increasing Sr content. The unit cell volume decreased on Sr-doping. The electrical conductivity of the oxides was measured from room temperature up to 800°C. The small polaron hopping conductivity model can adequately describe the electrical conductivity behavior. The activation energy decreases as x increases.