Research On The Surface Behaviors Of Materials Modified By Xenon Ion Implantation And Strong Magnetic Field

The irradiation damage and the strong magnetic field influence are not only two of the main environmental factors in magnetic confinement fusion reactors, but also widespread in other researches and engineering projects. So it is important to study on the material behaviors induced by those two factors. In this dissertation, we applied various techniques and methods to analyze the surface modification processes influenced by ion irradiation or strong magnetic field. The changes in surface morphology and structure of the materials are focused in our research.Firstly, irradiation damages were introduced in single-crystalline Si (001) substrates by Xe⁺ bombardment. It was found that two main irradiation effects were created by adjusting the parameters of the bombardment process. High energy ions at high irradiation dose could induce to swelling morphology, while low energy ions induced to sunken morphology. By experiments and simulations, it was indicated that the former two morphologies were caused by the surface sputtering and the interior damages in ion irradiation process.Secondly, we investigated the irradiation damage on polycrystalline Mo-Re alloy films. It was found that surface damage effects were different in films of the Re atomic content from 0 % to 8.4 %. The alloy films with the Re content of 5.2 % was found to have outstanding resistance property against irradiation damage. While the Re content increased to 8.4 %, localized amorphization could be observed in the films after irradiation process, which indicated that too much Re content might lower the resistance against irradiation damage.Thirdly, strong magnetic field was applied in the growth process of paramagnetic V₂O₅ nanorods, which were fabricated from V2O3 films by annealing process at 530 oC in air. Influenced by strong magnetic field which was parallel with the surface normal of the films, enlarged V₂O₅ nanorods with reduced defects concentration could be synthesized. The Lorentz force of the magnetic field was considered to be the main cause.Finally, we used strong magnetic field to adjust the orientation of the arrays of slanted Fe nanorods. Magnetic anisotropic Fe nanorods could be prepared by glancing angle deposition process (GLAD). By sputtering an Au film under the Fe nanorods, the connection between the nanorods and the substrate could be improved. Then we applied a strong magnetic field in the high vacuum annealing process of Fe nanorods. It could be observed that the slanted Fe nanorods were realigned towards the substrate surface normal by the magnetic force, while the magnetic anisotropy of the nanorods was kept.