Creating homogeneous depth profiles in YBaCuO films by ion beam implantation for uniform supression of Tc

Abstract

Critical temperature depth profiles were calculated for single and multiple energy oxygen ion implantation of YBaCuO thin films. Using the TRIM98 code and the diffusion equation the changes of the profiles during an annealing between 150 and 300°C were obtained. The results are in reasonable agreement with the experimental data. Experimentally we investigated further implantation of O +, Ne + and Al + with a homogeneous implantation profile. The critical temperature is depressed by the created defects and in the case of Al also by substitution of Cu. For O + and Ne + implantation the depression of the critical temperature is diminished by an annealing process. Depending on the quality of the films, T c reaches in some cases the values of the unimplanted samples. For Al + the critical temperature changes less by the annealing process compared to the O + or Ne + implantations and does not reach the starting values. Some results of an annealing made by laser treatment are presented, too.