Novel Y2-xPrxRu2O7 (x=0-2) Pyrochlore Oxides Prepared Using a Soft Chemistry Route and their Electrical Properties

Y2-xPrxRu2O7 (0 < x < 2) pyrochlore powders were prepared using a precipitation method, which allowed control of their composition and morphology. Materials structure and morphology were characterized by X-ray diffraction analysis and field emission scanning electron microscopy, respectively. All the synthesized powders exhibited a single pyrochlore phase with particle size depending on the Pr content. Powders with Pr content smaller than 25 mol% were nanometric. X-ray photoelectron spectroscopy analysis revealed a mixed oxidation state of both Pr and Ru, and a variation of the oxidation state of the elements in response to oxygen partial pressure changes. Electrical conductivity measurements were performed by dc 4-probe method at several temperatures, showing that increasing the Pr content in the A site of the pyrochlore structure increased the oxide electrical conductivity.