DAMAGE PROFILES IN MGO SINGLE-CRYSTALS AFTER KRYPTON IMPLANTATION

Single crystals of magnesium oxide were implanted with 150 keV krypton ions at room temperature. Fluences ranged from 5 x 10(14) to 5 x 10(1 5) at. cm-2 with dose rates well below 10(13) at. cm-2 s-1 to prevent target heating. Defect profiles were obtained by fitting aligned alpha -particle backscattering spectra to a dechanneling rate equation. For the lowest fluence the depth profile of the damaged region agrees reas onably with theoretical estimates, whilst at higher fluences a signifi cantly increased depth of the damaged region is found. The energy depe ndence of dechanneling as well as the general shape of the aligned bac kscattering spectra indicate a defect structure consisting of a combin ation of dislocation loops and severely disordered regions.