Pressure of stable He–vacancy complex in bcc iron: Molecular dynamics simulations

Molecular dynamic simulation was employed to study the stable state of He–vacancy (He–V) complex in bcc iron. The pressure of He–V complex was calculated using the concept of atomic-level stress. In the case of no initial vacancies introduced in the simulation box, self-interstitial atoms (SIAs) are emitted by the small He cluster. As the number of the He cluster is above a critical value, interstitial-type dislocation loops (I-loop) will be generated. After the interstitial-type defects (SIA or I-loop) were created, it is found that the ratio of He atoms to athermal vacancies keeps nearly constant in the He–V complex.