Evaluation of bonding state of BCC(Fe) edge dislocation core by DV-Xα cluster method : Advances in computational materials science and engineering II

The bonding state has been studied by the discrete variational (DV)-Xa method in the vicinity of the core of the Peierls-Nabarro edge dislocation in the BCC(Fe) crystal the slip systems of which are {112}(111) and [110](111). Bond order and net charge distribution were evaluated in the perfect crystal model cluster and edge dislocation core model cluster with 32 atoms. In the {112}(111) slip system, the total bond order of the nearest neighbor atom pairs in the dislocation model was found to be relatively larger than that in the perfect crystal model. On the other hand, the total bond order of the second neighbor atom pairs in the dislocation model was a little smaller than that in the perfect crystal model. It was also found that there was asymmetry in the bond order between the (110) plane on the left side and the one on the right side of the (110) plane which contains the core atom of dislocation. Net charge and its effect in the dislocation model were larger and wider than those in the perfect crystal model. Almost the same results were also attained for the {110}(111) slip system.