“…Consequently, surface film softening in <001> dislocation-containing materials is thought to occur from a general dislocation pumping process occurring at the film-substrate interface, which results in an effective increase in the overall mobile dislocation density available to effect plastic flow. Such results are analogous to reduced flow stresses observed by Ruddle and Wilsdorf for nickel-plated single crystals of copper many years ago (19).…”