Molecular dynamics simulations of oxygen Frenkel pairs in cerium dioxide

作者：Shiiyama Kenichi^*; Yamamoto Tomokazu; Takahashi Tatsuro; Guglielmetti Aurore; Chartier Alain; Yasuda Kazuhiro; Matsumura Syo; Yasunaga Kazufumi; Meis Constantin

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2010, 268(19): 2980-2983.

DOI：10.1016/j.nimb.2010.05.022

• Fluorite structure
• Dislocation loop
• Electron irradiation

Molecular dynamics simulations of oxygen Frenkel pairs (FPs) in cerium dioxide (CeO(2)) were carried out in order to understand their kinetic behavior. The results show that an oxygen FP recombine with the vacancy and the interstitial after the vacancy jump preferentially along the < 1 0 0 > direction. When multiple oxygen FPs are introduced, the interstitials aggregate into a (1 1 1) plate-like cluster at relatively lower temperature lower than 600 K. while they recombine with vacancies at elevated temperatures higher than 900 K within 10 ps. Molecular mechanics calculations of oxygen FPs on a (1 1 1) plane show that the formation energy per a FP decreases with increase of the number of FPs. The theoretical results are consistent with the transmission electron microscopy observations of formation of 1/9 < 1 1 1 >{1 1 1} oxygen interstitial platelets in CeO(2) under electron irradiation.

• 出版日期2010-10-1
• 单位中国地震局