We present a study of Y2-xZnxRu2O7 pyrochlores as a function of the Zn doping level x. X-ray diffraction measurements show that single-phase samples could be obtained for x < 0.2. Within the allowed range for x, dc conductivity measurements revealed a sizable decrease in resistivity at all the investigated temperatures for Zn doped samples with respect to undoped ones. Neutron diffraction data of the x = 0.2 sample showed that replacing Y3+ by Zn2+ does not result in the formation of oxygen vacancies. X-ray photoemission spectroscopy measurements revealed that part of the Ru ions are in the 5+ oxidation state to balance, in terms of electronic charge, the incorporation of Zn2+. The results give experimental evidence that the heterovalent doping promotes the increase of conductivity in the Y2Ru2O7 pyrochlores, making these systems promising as intermediate-temperature solid oxide fuel cell cathodes.

Observation of Mixed Valence Ru Components in Zn Doped Y2Ru2O7 Pyrochlores

SANNA, SAMUELE;
2016

Abstract

We present a study of Y2-xZnxRu2O7 pyrochlores as a function of the Zn doping level x. X-ray diffraction measurements show that single-phase samples could be obtained for x < 0.2. Within the allowed range for x, dc conductivity measurements revealed a sizable decrease in resistivity at all the investigated temperatures for Zn doped samples with respect to undoped ones. Neutron diffraction data of the x = 0.2 sample showed that replacing Y3+ by Zn2+ does not result in the formation of oxygen vacancies. X-ray photoemission spectroscopy measurements revealed that part of the Ru ions are in the 5+ oxidation state to balance, in terms of electronic charge, the incorporation of Zn2+. The results give experimental evidence that the heterovalent doping promotes the increase of conductivity in the Y2Ru2O7 pyrochlores, making these systems promising as intermediate-temperature solid oxide fuel cell cathodes.
2016
Berti, G.; Sanna, S.; Castellano, C.; Van Duijn, J.; Ruiz-Bustos, R.; Bordonali, L.; Bussetti, G.; Calloni, A.; Demartin, F.; Duò, L.; Brambilla, A
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/588961
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