Free carbon networks (FCN) in situ formed in the amorphous SiOC polymer-derived ceramics (PDCs) have been reported to have significant effects on the material microstructures as well as the related structural and functional properties. In this paper, detailed effects of the FCN on the radiation damage process and mechanisms of the amorphous SiOC PDC are investigated by using ab initio molecular dynamics simulations. The radiation simulations were conducted by introducing a random Si atom with kinetic energy of 80 eV as the primary knock-on atom. The FCN are proven to be beneficial to absorb the ion induced kinetic energy and convert it into thermal spike, which can be dissipated as thermal energy. The FCN interfaces with Si-O-C matrix can also capture the displaced atoms easily, thus reducing the cascade damage. The SiOC PDC are promising to be radiation tolerant materials for the prevention of radiation defect accumulation by the contained amorphous phase and FCN structure.

据报道，在无定形SiOC聚合物衍生的陶瓷（PDC）中原位形成的自由碳网络（FCN）对材料的微观结构以及相关的结构和功能特性具有重大影响。本文通过从头算分子动力学模拟研究了FCN对无定形SiOC PDC辐射损伤过程和机理的详细影响。辐射模拟是通过引入动能为80 eV的随机Si原子作为主要敲除原子而进行的。事实证明，FCN有益于吸收离子感应的动能并将其转换为热尖峰，该尖峰可以作为热能消散。FCN与Si-OC基质的界面也可以轻松捕获被置换的原子，从而减少级联损伤。