Electron paramagnetic resonance measurements have been used to determine the rate of change of the Fe3+concentration in MgO:Fe crystals due to reduction and oxidation with ambient gases at temperatures between 1000 and 1500 K. The results indicate that diffusion of vacancies with an activation energy of 3.23 eV is the ratehyphen;limiting step. There is some evidence that when a diffusion coefficient is obtained from a concentration profile, a contribution due to anomalously high mobility (presumably along dislocations) can be detected.
展开▼
