Determination of Stacking Fault Energies in Silicon and Nickel Single Crystals by Channelling Technique

Abstract

The dechannelling cross sections of axially channelled MeV H and He ions at dislocations in silicon and nickel crystals were studied. The obtained dechannelling cross section for dislocation in nickel was proportional to the square root of the ion energy, while that for dislocation in silicon was deviated from \sqrtE-dependence because of the dissociation of the dislocation into a pair of partial dislocations with ribbon of stacking fault between them. The width of the dissociated dislocation was determined by the comparison of the experimental cross sections with the results of the numerical calculation of the dechannelling cross section at the dissociated dislocation. The obtained width was 9±2 nm for dissociated edge dislocation in silicon. The experimental results for nickel suggested that dislocation in nickel does not dissociate and that the upper limit of the width of dissociation was estimated to be 2 nm. The stacking fault energies calculated from these widths were 42±10 erg/cm² for silicon and larger than 80 erg/cm² for nickel.