Lanthanide-Containing Zirconotitanate Solid Solutions

Solid solutions between several lanthanide-containing dititanate and dizirconate compounds have been synthesized and identified using X-ray diffraction (XRD). Complete solubility was found in the pyrochlore–pyrochlore-type systems Er2Ti2O7–Nd2Zr2O7and Nd1.2Er0.8Ti2O7–Nd2Zr2O7. Some solubility of Nd2Ti2O7, a monoclinic dititanate, in defect fluorite Er2Zr2O7was observed, and it was determined that there is some solubility of Nd2Ti2O7in pyrochlore-type Nd2Zr2O7. The systems Nd2Zr2O7–TiO2and Nd2Ti2O7–ZrO2also were investigated to help define a region of pyrochlore solid solution formation in the system NdO1.5-TiO2-ZrO2. Additionally, attempts were made to synthesize pyrochlore-type solid solutions between Ce2Ti2O7and Ce2Zr2O7and to substitute titanium with zirconium in the perovskite-type phases SrNd2Ti4O12and Sr2Ce2Ti5O16.