Metal Surface Studied by STM and Atomistic Simulations

We present a combined study by Scanning Tunneling Microscopy and atom- istic simulations of the emission of dissociated dislocation loops by nanoinden- tation on a (001) fcc surface. The latter consist of two stacking-fault ribbons bounded by Shockley partials and a stair-rod dislocation. These dissociated loops, which intersect the surface, are shown to originate from loops of inter- stitial character emitted along the <110> directions and are usually located at hundreds of angstroms away from the indentation point. Simulations re- produce the nucleation and glide of these dislocation loops.