From Ag2Sb2O6 to Cd2Sb 2O7: Investigations on an anion-deficient to ideal pyrochlore solid solution

Laurita G., Vielma J., Winter F., Berthelot R., Largeteau A., Pöttgen R., Schneider G., Subramanian M.A.

Abstract

A complete solid solution between the anion-deficient pyrochlore Ag 2Sb2O6 and the ideal pyrochlore Cd 2Sb2O7 has been synthesized through the standard solid state ceramic method. Each composition has been characterized by various different techniques, including powder X-ray diffraction, optical spectroscopy, electron paramagnetic resonance and 121Sb Mössbauer spectroscopy. Computational methods based on density functional theory complement this investigation. Photocatalytic activity has been studied, and transport properties have been measured on pellets densified by spark plasma sintering. The analysis of the data collected from these various techniques enables a comprehensive characterization of the complete solid solution and revealed an anomalous behavior in the Cd-rich end of the solid solution, which has been proposed to arise from a possible radical O- species in small concentrations. © 2013 Elsevier B.V. All rights reserved.