Defects in ion implanted and electron irradiated MgO and A1₂0₃

MgO and AI₂O₃ crystals have been implanted with Ne ions at temperatures between 90 K and 720 K and the damaged layers were investigated by optical absorption spectroscopy and X-ray diffraction. The damage production is discussed in terms of the number of F-centers, of the change of the lattice parameter, and of the diffuse scattering intensity close to Bragg reflections. The stability of the defects was tested in addition by subsequent subthreshold e^--irradiations. No effect of an applied electric field on the defect production is observed for both oxides.