Molecular dynamics simulation of irradiation induced phase transition in MgAl2O4

Alain Chartier, Tomokazu Yamamoto, Kazuhiro Yasuda, Constantin Meis, Kenichi Shiiyama, Syo Matsumura

研究成果: 書籍/レポート タイプへの寄稿会議への寄与

抄録

The kinetic of phase transitions under irradiation of MgAl2O4 has been studied using molecular dynamics (MD) simulation by means of continuous cation Frenkel pair (FP) accumulation. Three different cases have been considered: cation FP accumulation starting (i) from the normal (N) spinel, (ii) from the amorphous (A) spinel and (iii) from the interface between rock-salt (NaCl) spinel and A-spinel. When submitted to FP accumulation, the N-spinel transits directly towards the NaCl-spinel for temperature lower than 600K. For temperatures higher than 600K, the dose needed to obtain the rock-salt structure increases with temperature, and the structure transits to an intermediate disordered (D) structure prior to the NaCl-spinel. No amorphization of the spinel under FP accumulation is obtained for doses up to 68 displacements per cation at 30K. The dose - temperature dependence relies on thermally activated FP recombination processes. The epitaxial and homogeneous irradiation induced re-crystallization of amorphous MgAl2O4 was obtained by continuous FP accumulation. Present results point out that the re-crystallization induced by FP accumulation appears in both cases to be thermally enhanced but non diffusive. It is governed by a local rearrangement of each point defect in the homogeneous case, while spontaneous FP recombination process in the crystalline part or at the interface drives the recrystallization in the epitaxial case. In summary, the thermally enhanced - but non diffusive - Frenkel pair recombination or local relaxation of point defects may play a central role to the radiation resistance of MgAl2O4.

本文言語英語
ホスト出版物のタイトルProceedings of 4th International Conference on Multiscale Materials Modeling, MMM 2008
編集者Anter El-Azab
出版社Department of Scientific Computing, Florida State University
ページ583-588
ページ数6
ISBN(電子版)9780615247816
出版ステータス出版済み - 2008
イベント4th International Conference on Multiscale Materials Modeling, MMM 2008 - Tallahassee, 米国
継続期間: 10月 27 200810月 31 2008

出版物シリーズ

名前Proceedings of 4th International Conference on Multiscale Materials Modeling, MMM 2008

会議

会議4th International Conference on Multiscale Materials Modeling, MMM 2008
国/地域米国
CityTallahassee
Period10/27/0810/31/08

!!!All Science Journal Classification (ASJC) codes

  • 材料科学(全般)

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