A comparative study of low energy radiation responses of SiC, TiC and ZrC

作者：Jiang, M.; Xiao, H. Y.^*; Zhang, H. B.^*; Peng, S. M.; Xu, C. H.; Liu, Z. J.; Zu, X. T.

来源：Acta Materialia, 2016, 110: 192-199.

DOI：10.1016/j.actamat.2016.03.011

• SiC and transition metal carbides
• Low energy irradiation
• Defect formation and distribution
• Ab initio MD

In this study, an ab initio molecular dynamics method is employed to compare the responses of SiC, TiC and ZrC to low energy irradiation. It reveals that C displacements are dominant in the cascade events of the three carbides. The associated defects in SiC are mainly Frenkel pairs and antisite defects, whereas damage end states in TiC and ZrC generally consist of Frenkel pairs and very few antisite defects are created. It is proposed that the susceptibility to antisite formation in SiC contributes to its crystalline-to-amorphous transformation under irradiation that is observed experimentally. The stronger radiation tolerance of TiC and ZrC than SiC can be originated from their different electronic structures, i.e., the < Ti-C > and < Zr-C > bonds are a mixture of covalent, metallic, and ionic character, whereas the < Si-C > bond is mainly covalent. The presented results provide underlying mechanisms for defect generation in SiC, TiC and ZrC, and advance the fundamental understanding of the radiation resistances of carbide materials.

• 出版日期2016-5-15
• 单位中国工程物理研究院; 中国工程物理研究院核物理与化学研究所; 兰州城市学院; 电子科技大学