Interdiffusion in oxides (A,B)O (II): Experimental investigation of point-defect relaxation on concentration profiles for MnO-FeO

Publisher Website
Google Scholar
Abstract
Vacancy relaxation phenomena during interdiffusion of FeO and MnO have been studied on the basis of very accurate concentration-distance profiles of the cations, measured by X-ray microanalysis. The profiles clearly depended on annealing time and form of the samples. This observation directly demonstrates that local thermodynamic equilibrium of defects is not established in the reacting system. In addition, the deviation from local equilibrium is most pronounced at the early stage of the reaction in a thick sample. This can be explained by the long relaxation time the cation vacancies need to reach a free surface surrounded by oxygen gas as a vacancy sink.