The Environment Factors Effect On The Structures And Properties Of DLC And A-Sic:H Films

With the development of deposition techniques,diamond-like carbon(DLC) and a-SiC:H films will be applied more widely. At present,the fundamental barrier that has not been overcome in respest of the coatings as applied to the irradiation environments is their radiation stability.For the sake of application to the fields such as aeronautics,astronautics,and nucleus reactorjnore attentions were paid on the investigation of the radiation stability of the films. DLC and a-SiC:H films were prepared by the rf glow discharge and the reactive sputtering method respectively.There were two reasons that we chose Y rays,ultraviolet(UV) photons,and neutrons as radiation sources.One is that Y rays, UV photons and neutrons irradiation are serious at outer space and/or nucleus irradiation enviromentThe other is that the study on Y rays irradiation on the films is a new and an important directioaOtherwiseJirnited reports have been made of the investigation on the UV photonsjieutrons irradiation influences on these films.The DLC and a-SiC:H films have been prepared by rf glow discharge.The irradiated samples were characterized by Ramaiynfrared and UV-VIS-NIR spectroscopy mainly. According to the physical mechanisms related to the interaction of photons,neutrons,and ions with matter,the results and phenomena are explained and discussed.The structures and properties of the films depend strongly upon the hydrogen content and the binding state. The UV-VIS-NIR spectroscopy and Tauc method are used to calculate the optical gap of DLC films.The result that hydrogen content is 10~25aL% is deduced by the data of the optical gap and fully constrained network(FCN) model.Thus,a new method,by which the hydrogen content of the DLC films can be determined,was obtained by the auther. The refractive index and the changing behaviour of the a-SiC:H films were calculated by using UV-VIS-NIR spectroscopy interference wave and it was found that the hydrogen content and IR transmittance were decreased with Y rays irradiation dose.lt is very interesting that the SP'C-H bonds were observed by the Raman spectra for the first time and expand the application scopes of Raman spectroscopy in structure analyse fields.The Y rays, neutrons,N ions and UV photons have different irradiation behaviour on the films by the study of this dissertatioaThe Y rays was much weaker than other particles if considering the breaking ability to the SP'C-H bonds only. So, Y rays, compared with the other particles,have some particularity in acting with materials.The UV photons, exceeding our expectation, can break the SP'C-H bonds easily. The results of this dissertation can help to apply the films in the irradiation enviroment and consequently serve the aeronautics,astronautics,and nuclear industry.