Zhang Shounuo, Li Menglu, Xiao Haiyan, Liu Zijiang, Zu Xiaotao
School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, China.
Department of Physics, Lanzhou City University, Lanzhou 730070, China.
Materials (Basel). 2021 Mar 19;14(6):1516. doi: 10.3390/ma14061516.
In this study, the response of PuZrO and LaZrO to electronic radiation is simulated, employing an molecular dynamics method. It is shown that PuZrO undergoes a crystalline-to-amorphous structural transition with 0.3% electronic excitation, while for LaZrO, the structural amorphization occurs with 1.2% electronic excitation. During the microstructural evolution, the anion disorder further drives cation disorder and eventually results in the structural amorphization of PuZrO and LaZrO. The difference in responses to electron radiation between PuZrO and LaZrO mainly results from the strong correlation effects between Pu 5 electrons and the smaller band gap of PuZrO. These results suggest that PuZrO is less resistant to amorphization under local ionization rates that produce a low level of electronic excitation, since the level of the concentration of excited electrons is relatively low in PuZrO. The presented results will advance the understanding of the radiation damage effects of zirconate pyrochlores.
在本研究中，采用分子动力学方法模拟了PuZrO和LaZrO对电子辐射的响应。结果表明，PuZrO在0.3%的电子激发下发生晶态到非晶态的结构转变，而对于LaZrO，在1.2%的电子激发下发生结构非晶化。在微观结构演化过程中，阴离子无序进一步驱动阳离子无序，最终导致PuZrO和LaZrO的结构非晶化。PuZrO和LaZrO对电子辐射响应的差异主要源于Pu 5电子之间的强关联效应以及PuZrO较小的带隙。这些结果表明，在产生低水平电子激发的局部电离率下，PuZrO对非晶化的抗性较低，因为PuZrO中激发电子的浓度水平相对较低。所呈现的结果将推进对锆酸焦绿石辐射损伤效应的理解。
