The bonding state was studied by using the discrete variational DV-Xα method in the vicinity of the core of a Peierls-Nabarro edge dislocation in a body-centered cubic Fe crystal whose slip systems were {112}<111> and {110}<111>. The 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 case of the {112}<111> slip system, the total bond order of the nearest-neighbor atom pairs in the dislocation model was found to be 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 an asymmetry in the bond order between the (110) plane on the left and the one on the right of the (110) plane which contained the core atoms of the dislocation. The net charge, and its effect in the dislocation model, was larger and wider than that in the perfect crystal model. Essentially the same results were obtained for the {110}<111> slip system.

Evaluation of Bonding State of BCC(Fe) Edge Dislocation Core by DV-Xα Cluster Method. T.Fukuda, M.Hida, A.Sakakibara, Y.Takemoto: Materials Transactions, 2001, 42[11], 2232-7