Ab Initio Calculation of the Interaction of an Edge Dislocation with Transition Metal Impurity Atoms in Silicon

Abstract

The first-principle calculation of the interaction of an edge dislocation with transition metal impurities Cr, Mn, Fe, Co, Ni and Cu in a supercell composed of 180 Si atoms is presented. The density functional theory in the general gradient approximation using the ABINIT software package has been used for numerical calculation. The interaction curves of edge dislocations with impurity atoms in silicon are obtained. The shape of the interaction curves corresponds to the Lennard-Jones potential. The equilibrium positions of impurity atoms in the vicinity of the edge dislocation cores are obtained. The binding energy of Cr, Mn, Fe, Co, Ni, Cu impurity atoms with an edge dislocation in silicon is calculated and analyzed. The electronic structure of the supercell with a dipole of two edge dislocations with Cr, Mn, Fe, Co, Ni and Cu impurities is presented. The general features of the electronic spectra for all impurity atoms are discussed. Due to the existing defective structure of the supercell, additional states appear in the band gap for all impurities, in particular, for Ni and Cu impurities, a sharp half-filled impurity peak is observed in the band gap. The intensity and fine structure of impurity peaks vary depending on the type of impurity and its position. The possibility of magnetic ordering on the dislocation core dangling bonds and Ni, Cu impurity atoms in the vicinity of the edge dislocation core has been discussed.