Abstract: | The results of macroscopic strain rate and temperature cycling tests on MgO single crystals are compared with the results of in-situ deformation tests in a HVEM on the basis of the basis of the thermally activated dislocation glide model. The activation volume estimated by strain rate cycling tests is compatible with the mean obstacle distance of the screw dislocations. However, the local stress estimated by in-situ deformation tests was found to be larger than the macroscopic yield stress. |