The dechannelling cross-sections of axially channelled MeV H and He ions at dislocations in silicon and nickel crystals were studied. The dechannelling cross-section obtained for dislocations in nickel was proportional to the square root of the ion energy, while that for dislocations in silicon deviated from the above dependence because of dissociation of the dislocations into a pair of partial dislocations having a ribbon of stacking fault between them. The width of the dissociated dislocation was determined by a comparison of the experimental cross-sections with the results of numerical calculations of the dechannelling cross-section at the dissociated dislocation. The width obtained was 9nm for dissociated edge dislocation in silicon. The experimental results for nickel suggested that dislocations in nickel did not dissociate and that the upper limit of the width of dissociation was about 2nm. The stacking-fault energies calculated from these widths were 42mJ/m2 for silicon and greater than 80mJ/m2 for nickel.

Determination of Stacking Fault Energies in Silicon and Nickel Single Crystals by Channelling Technique. K.Kimura: Journal of the Physical Society of Japan, 1983, 52[3], 895-904