Hydrothermal Synthesis and Structure of a Potassium Tantalum Defect Pyrochlore

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• 作者：Niangao Duan ; Zheng-Rong Tian ; William S. Willis ; Steven L. Suib ; John M. Newsam ; and Steven M. Levine
• 刊名：Inorganic Chemistry
• 出版年：1998
• 出版时间：September 7, 1998
• 年：1998
• 卷：37
• 期：18
• 页码：4697 - 4701
• 全文大小：66K
• 年卷期：v.37,no.18(September 7, 1998)
• ISSN：1520-510X

文摘

The synthesis and crystal structure of potassium tantalate (KTa₂(O,OH)₆·1.8H₂O) with a defect pyrochlore structureare reported. The compound was crystallized directly from tantalum pentoxide in basic solution under hydrothermalconditions at temperatures as low as 200 mages/entities/deg.gif">C. Ion exchange of this substance in acid yielded an H-type defectpyrochlore. Both highly crystalline K-type and H-type materials absorb argon and have BET surface areas ofabout 14 m²/g. The crystal structures were refined by the Rietveld least-squares method from powder X-raydiffraction data. The final R_wp and mages/gifchars/chi.gif" BORDER=0 >² were 7.70% and 2.79, respectively. The high thermal stability and controlof acidity of these materials, along with the simple and cheap synthesis, may find many applications in sorption,catalysis, and microelectronics.