POINT-DEFECT CONCENTRATION RELAXATION AND CREEP TRANSIENTS IN BINARY OXIDES

In non-stoichiometric oxides (NiO, CoO, Cu-2 O...) two thermodynamic p arameters (temperature T and partial pression of oxygen P-O2) are nece ssary in order to fix the population of point defects. When one of the se two parameters (T or P-O2) is suddenly changed and a physical prope rty is continuously recorded, a ''transient'' can be observed due to t he diffusion of the point defects in order to reach the new thermodyna mic equilibrium population. Many works have been devoted to the majori ty point defects (non-stoichiometry). In this paper we present an over view about the high temperature transitory plastic deformation which i s related with the minority point defects.