bcc Fe的刃型位错中氦-空位团的稳定性

 采用周期性原子阵列方法建立bcc Fe中的刃型位错，利用分子动力学计算了0 K时bcc Fe的位错芯里氦-空位团的稳定性，并与理想Fe晶体里氦-空位团的稳定性进行比较发现,位错的作用导致氦-空位团不稳定。点缺陷（He、空位与自间隙Fe原子）与氦-空位团的结合能与团中氦-空位比例密切相关，当氦与空位数之比在3~6时，结合能趋于稳定。

Stability of helium-vacancy clusters in edge dislocations in bcc Fe

The a/2〈111〉{110} edge dislocation in bcc Fe was created using periodic array of dislocations methods. Molecular dynamic calculations were performed to study the stability of He-vacancy clusters in the dislocation core in bcc Fe, and the results were compared with simulations performed in perfect bcc Fe. The comparison show that the He-vacancy clusters are unstable for the effects of the dislocation field. The binding energies of an interstitial He atom, a vacancy and a self-interstitial Fe atom to the He-vacancy clusters depend mainly on the He-to-vacancy ratios of the clusters. In the dislocation core, for the ratio larger than 3 and less than 6, the binding energies are almost unchanging.