Dislocation motion and multiplication at the deformation of MgO single crystals in the high voltage electron microscope

In-situ-deformation experiments are made in a high voltage electron microscope. In MgO single crystals the processes governing the dislocation mobility are the overcoming of local obstacles at the screw dislocations and the Peierls mechanism at edge dislocations. The dislocations multiply mainly from edge dislocation dipoles trailed behind moving screw dislocations.