Abstract Current studies describe the application of simultaneous TG–DTA–FTIR technique in the in-situ synthesis of tri uranium octaoxide (U3O8) and impurity characterization of the ammonium diuranate (ADU) matrix. Formation of U3O8 could be due to the decomposition of ADU to uranium trioxide (UO3) and finally to U3O8 by the temperature of 500 °C. Presence of carbon and carbonate could be seen as impurities in the matrix. Carbon content has been determined quantitatively using TG and FTIR techniques and the results are in good agreement. Ammonium nitrate was found as impurity in ammonium diuranate matrix. The PXRD studies confirm the formation of U3O8 as end product during the decomposition of ammonium diuranate. From our studies, it is suggested that ammonium diuranate decomposes to tri uranium octaoxide (U3O8) through evolution of nitrogen, hydrogen and oxygen, and not through ammonia evolution in the literature.

中文翻译：

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使用同步 TG-DTA-FTIR 和 PXRD 测量原位合成 U3O8 过程中重铀酸铵的杂质表征和热分解机制

摘要 目前的研究描述了同步 TG-DTA-FTIR 技术在原位合成八氧化三铀 (U3O8) 和重铀酸铵 (ADU) 基质杂质表征中的应用。U3O8 的形成可能是由于 ADU 分解为三氧化铀 (UO3)，最终在 500 °C 的温度下分解为 U3O8。碳和碳酸盐的存在可被视为基质中的杂质。碳含量已使用 TG 和 FTIR 技术定量测定，结果非常一致。硝酸铵被发现是重铀酸铵基质中的杂质。PXRD 研究证实了在重铀酸铵分解过程中形成了作为最终产物的 U3O8。我们的研究表明，重铀酸铵通过释放氮分解为八氧化三铀 (U3O8)，