Showing papers by "Werner Wesch published in 2018"
15 Nov 2018-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, a single crystalline BaWO4 was implanted at room temperature with 370 KV Kr ions and ion fluences ranging from 1.5 to 4.5 kV Kr. The damage built-up during implantation was investigated by quasi-in situ Rutherford backscattering spectrometry in channelling configuration (RBS/C) using a two-beam chamber.
Abstract: Single crystalline 〈1 0 0〉 oriented BaWO4 was implanted at room temperature with 370 keV Kr ions and ion fluences ranging from 1 × 1012 to 4 × 1016 ions/cm2. The damage built-up during implantation was investigated by quasi in situ Rutherford backscattering spectrometry in channelling configuration (RBS/C) using a two-beam chamber. Up to the highest ion fluence applied no amorphization is observed indicating that BaWO4 has a high resistance to amorphization by ion irradiation. The shape of the RBS/C spectra indicates the existence of extended defects. Damage formation in the bulk proceeds in two steps, which can be attributed to formation and recombination of point defects and formation and growth of defect clusters including extended defects. Additionally a significant damage accumulation at the surface is observed. Some damage recovery occurs after annealing up to 600 °C. Although after annealing at 700 °C the amount of damage drastically decreased, complete damage recovery could not be obtained.
5 citations
15 Nov 2018-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, the damage formation and annealing of Eu implanted KTiOAsO4 crystals was investigated, which showed that the Eu peak firstly migrated to the surface after the implantation at 600°'C for 30'min, and then appeared narrower after annaling at 700°'c for 30'min.
Abstract: Damage formation and annealing of Eu implanted KTiOAsO4 crystals is investigated. Ion implantation was done with 400 keV Eu2+ ions and an ion fluence of 5 × 1015 ions/cm2 at room temperature. The damage of as-implanted and annealed samples was analysed by Rutherford backscattering spectrometry in channelling configuration using 2.1 MeV He+ ions. After implantation, a thick RBS-amorphous layer is obtained. The damage in the Eu2+ implanted KTiOAsO4 layer decreases significantly after annealing at 700° C for 30 min in Ar atmosphere. Interestingly, the Eu peak firstly migrated to the surface after annealing at 600° C for 30 min, and then appeared narrower after annealing at 700° C for 30 min. Furthermore, arsenic loss by evaporation and titanium enrichment at the surface are observed during the annealing process.