By using a first-principles real space method, an investigation was made of the electronic structure of C which was doped into various types of interstitial site in the [100](010) edge dislocation core of body-centered cubic Fe. The energetic calculations showed that C had a strong tendency to enter the expansion region; which was related to the lattice distortion that was introduced by the dislocation. It was found that some charge accumulation existed in the expansion region; resulting in an inhomogeneous charge distribution in the dislocation core. The trapping effect upon C appeared at the dislocation core center. Both dislocations, and C, greatly affected the electronic states of Fe atoms in the dislocation core. Analysis of the electronic structure indicated that hybridizations between C and Fe came from C 2p and Fe 3d4s4p. The localized effect of C-dislocation complexes clearly affected the electronic structure as well as the energy of the system.

Electronic States and Doping Effect of Carbon in the Edge-Dislocation Core of BCC Iron. J.A.Yan, C.Y.Wang, W.H.Duan, S.Y.Wang: Physical Review B, 2004, 69[21], 214110 (9pp)