中国物理B ›› 2017, Vol. 26 ›› Issue (6): 60703-060703.doi: 10.1088/1674-1056/26/6/060703

• GENERAL • 上一篇    下一篇

Theoretical investigation on radiation tolerance of Mn+1AXn phases

Ke-Di Yin(殷克迪), Xi-Tong Zhang(张西通), Qing Huang(黄庆), Jian-Ming Xue(薛建明)   

  1. 1 State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China;
    2 CAPT, HEDPS, and IFSA Collaborative Innovation Center of MoE College of Engineering, Peking University, Beijing 100871, China;
    3 Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • 收稿日期:2016-11-22 修回日期:2017-03-10 出版日期:2017-06-05 发布日期:2017-06-05
  • 通讯作者: Jian-Ming Xue E-mail:jmxue@pku.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 91226202 and 91426304).

Theoretical investigation on radiation tolerance of Mn+1AXn phases

Ke-Di Yin(殷克迪)1, Xi-Tong Zhang(张西通)1, Qing Huang(黄庆)3, Jian-Ming Xue(薛建明)1,2   

  1. 1 State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China;
    2 CAPT, HEDPS, and IFSA Collaborative Innovation Center of MoE College of Engineering, Peking University, Beijing 100871, China;
    3 Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • Received:2016-11-22 Revised:2017-03-10 Online:2017-06-05 Published:2017-06-05
  • Contact: Jian-Ming Xue E-mail:jmxue@pku.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 91226202 and 91426304).

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摘要：

Ternary Mn+1AXn phases with layered hexagonal structures, as candidate materials used for next-generation nuclear reactors, have shown great potential in tolerating radiation damage due to their unique combination of ceramic and metallic properties. However, Mn+1AXn materials behave differently in amorphization when exposed to energetic neutron and ion irradiations in experiment. We first analyze the irradiation tolerances of different Mn+1AXn (MAX) phases in terms of electronic structure, including the density of states (DOS) and charge density map. Then a new method based on the Bader analysis with the first-principle calculation is used to estimate the stabilities of MAX phases under irradiation. Our calculations show that the substitution of Cr/V/Ta/Nb by Ti and Si/Ge/Ga by Al can increase the ionicities of the bonds, thus strengthening the radiation tolerance. It is also shown that there is no obvious difference in radiation tolerance between Mn+1ACn and Mn+1ANn due to the similar charge transfer values of C and N atoms. In addition, the improved radiation tolerance from Ti3AlC2 to Ti2AlC (Ti3AlC2 and Ti2AlC have the same chemical elements), can be understood in terms of the increased Al/TiC layer ratio. Criteria based on the quantified charge transfer can be further used to explore other Mn+1AXn phases with respect to their radiation tolerance, playing a critical role in choosing appropriate MAX phases before they are subjected to irradiation in experimental test for future nuclear reactors.

关键词: MAX phases, radiation tolerance, Bader analysis, the first principle calculation

Abstract:

Ternary Mn+1AXn phases with layered hexagonal structures, as candidate materials used for next-generation nuclear reactors, have shown great potential in tolerating radiation damage due to their unique combination of ceramic and metallic properties. However, Mn+1AXn materials behave differently in amorphization when exposed to energetic neutron and ion irradiations in experiment. We first analyze the irradiation tolerances of different Mn+1AXn (MAX) phases in terms of electronic structure, including the density of states (DOS) and charge density map. Then a new method based on the Bader analysis with the first-principle calculation is used to estimate the stabilities of MAX phases under irradiation. Our calculations show that the substitution of Cr/V/Ta/Nb by Ti and Si/Ge/Ga by Al can increase the ionicities of the bonds, thus strengthening the radiation tolerance. It is also shown that there is no obvious difference in radiation tolerance between Mn+1ACn and Mn+1ANn due to the similar charge transfer values of C and N atoms. In addition, the improved radiation tolerance from Ti3AlC2 to Ti2AlC (Ti3AlC2 and Ti2AlC have the same chemical elements), can be understood in terms of the increased Al/TiC layer ratio. Criteria based on the quantified charge transfer can be further used to explore other Mn+1AXn phases with respect to their radiation tolerance, playing a critical role in choosing appropriate MAX phases before they are subjected to irradiation in experimental test for future nuclear reactors.

Key words: MAX phases, radiation tolerance, Bader analysis, the first principle calculation

中图分类号:  (Computer interfaces)

  • 07.05.Wr
28.41.Qb (Structural and shielding materials) 47.54.Jk (Materials science applications)