Study On Microstructure Properties Of The Iron Films On Silicon Oil Surfaces

In this paper, iron thin films have been fabricated on silicone oil surfaces by thermal evaporation method. By transmission electron microscopy (TEM) and optics spectrometer, we systematically study the influences of deposition rates (f) and substrate temperatures (Ts) on the evolution of microstructure, crystalline properties and optical properties of the Fe films. The main results are listed below:(1) The microstructure and crystalline properties of the Fe films with different deposition rates have been investigated extensively by TEM. It is found that the microstructure of the films is amorphous when f= 0.01 nm/s. When f> 0.05nm/s, a typical coexistent microstructure of the crystallized and amorphous states within a same sample can be observed simultaneously, and the number density and the sizes of polycrystalline particles increase with the deposition rates f.We suggest that the phenomena described above should be related to the kinetic energy of the deposited atoms and the unique effects of liquid substrates on the deposited atoms.(2) The optical properties of the samples with different deposition rates have been measured systematically. For f= 0.01 nm/s, the visible light transmittance of the film is greater than 95% with excellent transparency; the average light transmittance decreases with f, as f goes up to 0.45nm/s, the visible light transmittance is about 60% and the sample shows gray black. It is suggested that the colors of the films are closely related to the microstructures and the crystalline properties of the films.(3) We study the Fe films with different substrate temperatures by TEM. The experiment shows that the Fe films exhibit amorphous structure for Ts= 10.0℃ and the microstructure of the films is polycrystalline for Ts≤ 0.0℃. The number density of crystalline grains decreases with Ts while the grain size increases with Ts. It is suggested that the viscosity coefficients of liquid substrate and diffusion coefficients of nanoparticles change with the substrate temperatures, which leads to the phenomenon above.(4) The study on the optical properties of samples with the different substrate temperatures shows that the visible light transmittance of the film decreases from 95% to about 60% as Ts goes down from 10.0℃ to - 20.0℃. The possible reason is that the substrate temperature affects the microstructure properties and crystallization properties of the films, thus further affects the transmission performances of the films.The contents of the thesis are arranged as follows:In chapter one, preparation methods and preparation conditions and physical characteristics of the films are mainly described. The research status of the metal thin film on the liquid substrate is introduced.In chapter two, the preparations of the Fe films on the silicone oil surfaces and film characterization samples are detailed.In chapter three, the effects of deposition fluxes and substrate temperatures on the microstructure, crystalline properties and optical properties of the Fe films are introduced, and the reasonable explanations have been given.In chapter four, the main conclusions and prospects are presented.