The annealing behavior of ion-implanted single crystals of the type YBa 2Cu 3O x

Abstract

Recent measurements have shown that the structural disorder induced by the implantation of ions into high- T c superconducting oxides of the type YBa 2Cu 3O x can lead to significant decomposition of the implanted region during subsequent thermal processing. We have used Rutherford backscattering spectrometry and ion channeling to examine the effects of ion implantation and thermal annealing on the near-surface composition of these materials. Our results indicate that the decomposition of the implanted region of YBa 2Cu 3O x single crystals is associated with Ba migration and occurs for ion doses above a definite threshold when thermal anneals are carried out at temperatures greater than 500 °C in a variety of atmospheres (O 2, O 2 + H 2O, Ar). Importantly, we have also observed that the implanted crystals can be annealed in O 2 at a temperature of 850 ° C with little decomposition of the implanted region occurring and that, under these conditions, the implantation-induced disorder is substantially removed.