Studies in the PuO2 – ZrO2 Pseudo-binary Phase Diagram
Studies in the PuO2 – ZrO2 Pseudo-binary Phase Diagram
复制标题
PuO2-ZrO2 准二元相图的研究
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Y. Arai
中科院分区：
文献类型：
--
作者：
T. Albiol;H. Serizawa;Y. Arai
摘要用高温X射线衍射法研究了富氧化锆区域中二氧化锆和二氧化钚之间的相关系。在1273K，在所研究的组成范围内，样品表现出两种稳定的相：单斜晶系和立方晶系。在较高温度下，根据温度和组成，观察到几种构型。结果表明，在1463K时存在一条共析线，共析点的组成在2.3~3.1mol%PuO2之间。然后，通过最小化Gibbs能，计算了整个浓度范围和3200K以下的准二元相图，得到了较好的实验数据。结果图显示了三个固溶体区域。较大的费域允许在高温下完全溶解。在富含ZrO2的一侧，根据温度的不同，少量的PuO2可以以单斜或四方的形式存在于溶液中。这些固溶体区域被两相区域分开。这一实验和计算研究提供了对PUO_2-ZrO_2的伪二元图的重新评价。它给出了以前不确定的区域的更清晰的观点，并为研究更复杂的相关系提供了一个很好的起点，无论是在类岩石燃料的框架下，还是在元素的轻微变质的框架下。
Abstract The phase relationship between ZrO2 and PuO2 was examined in the ZrO2-rich region by high temperature X-ray diffractometry. At 1273 K, for the studied range of compositions, the samples exhibited two stable phases: monoclinic and cubic. At higher temperatures, several configurations were observed depending on the temperature and the composition. It was concluded that there should be a eutectoid line at 1463 K and that the composition of the eutectoid point was in between 2.3 and 3.1 mol% PuO2. Then, the pseudo-binary phase diagram was calculated by minimisation of Gibbs energies, on the whole range of concentrations and up to 3200 K. A good fitting of experimental data was obtained. The resulting diagram shows three solid solution domains. A large fee domain allows complete solubility at high temperature. On the ZrO2 rich side, small amounts of PuO2 can be in solution either under monoclinic or tetragonal form depending on the temperature. These solid solution domains are separated by two-phase ones. This experimental and computational study provides a re-evaluation of the pseudo-binary diagram PuO2 – ZrO2. It gives a clearer view of the previously uncertain domains and it provides a good starting point for studying more complex phase relationships both in the frame of rock-like fuels and minor actinide transmutation.