Effects of co-implanted oxygen or aluminum atoms on hydrogen migration anddamage structure in multiple-beam irradiated Al2O3

Depth profiles of implanted H atoms were measured for single crystalline AL (2)O(3) samples irradiated at 923 K with dual or triple beams of 0.25 MeV H -, 0.6 MeV He-, 2.4 MeV O-ions or 2.6 MeV Al-ions. The peaks occur at 1.55 and 1.45 mum in the depth profiles measured for the H + Al dual beam irradi ation and H + O dual beam case, respectively. The ratio of the peak areas i s over 4, which is much larger than the implanted H atom ratio of 1.1, indi cating that implanted Al atoms suppress the mobility of H atoms. However, t he ratio becomes almost 1 between the triple beam samples with H + He + O-i ons and with H + He + Al-ions at comparable doses. The fact demonstrates th at implanted He atoms overwhelm the effects of the implanted self-cation/an ion excess atoms on the migration behaviors of implanted hydrogen and radia tion produced point defects, with the resulting sluggish cavity growth obse rved. (C) 2000 Elsevier Science B.V. All rights reserved.