ANNEALING OF RADIATION-DAMAGE IN MGO SINGLE-CRYSTALS AFTER KRYPTON IMPLANTATION

Single crystals of magnesium oxide were implanted with 150 keV krypton ions at room temperature. Fluences ranged between 5 x 10(14) and 5 x 10(15) ions cm-2 using a dose rate of approximately 10(13) ions cm-2 s -1. Samples were isochronally annealed in vacuum at temperatures of 40 0, 600, 800 and 1000-degrees-C. Damage depth profiles were determined before and after each annealing cycle by alpha-particle channeling usi ng a backscattering geometry. Relative defect densities were obtained from aligned spectra by numerical integration of the dechanneling rate equation. The experimental results confirm a mixed damage structure, which probably consists of randomly disordered regions and extended de fects. Complete annealing of these two components occurs at temperatur es above 600 and 800-degrees-C respectively.