The Electron Diffraction Steam Plating Film

Electron diffraction play an important role in modern physics, it is one of the important methods to explore the structure of matter. With the deepening of exploring on the microscopic world, calibration electron diffraction pattern turns into a key point to get material structure information, crystal structure and detect of the chemical composition of the solid sample, it has become the important mean of material microstructure. Electron diffraction is suitable for the research of the film surface structure owning to the strong scatter of the electron and atomic nuclei and the transmittance of them is relatively weak. If the film is too thick, electron diffraction will be unobvious or not happen, which can influence the understanding of microstructure of material, at the same time, it can be affected by incident wavelength and angle. In order to improve the electron diffraction pattern effect and obtain accurate information of crystal structure, and provide technical support to electronic diffraction method in crystal structure as well, the thesis studies the factors influencing film quality and thickness, discusses crystal index that electron diffraction pattern has got under different high pressure, and achieves the best parameters that electron diffraction uses to determine crystalline materials.The experiment uses evaporation to make silver thin film, by changing the plating current, deposition time, as well as the substrate material collodion thickness to obtain different structure of silver films, and then through the different filament voltage and accelerating voltage, electron diffraction pattern of films is measured, contrasting and analyzing, optimal deposition parameters, the filament voltage and the anode voltage is finally derived. The experiment indicates that:the vacuum and deposition time of the case being still intact, the smaller plating current is, the worse of thin film uniformity and compactness is; the degree of vacuum and coating current of the case being still intact, the longer the deposition time, the worse film uniformity and compactness; when coating vacuum maintained in p=1×10-3pa, plating current of 24 A and thin film deposition time of 20.17s, the film uniformity and compactness are the best; if keeping the electron diffraction vacuum p=8×10-3pa accelerated by high Press 25kV, filament voltage 140V, electron diffraction patterns of the visibility is the best; at the same time, for the same structure of the thin films, if the filament voltage is constant, the higher the acceleration voltage, the smaller radius of the electron diffraction patterns; with the accelerating voltage constant, as the filament voltage increases, the electron diffraction image is much clearer.Therefore, when using electron diffraction to determine the microscopic structure of crystal materials, the optimal experimental parameters is chosen:The thickness of the basement membrane using 0.08 ml of collodion amyl acetate solution made of collodion, coating vacuum p= 1×10-3, current 24A, thin film deposition time 20.17s, electron diffraction vacuum p=8×10-3, acceleration voltage 25kV, the filament voltage 140v.