Development of velicity selector for metal atom and its application in thermal engineering

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To study the control of the thin film condensation process with the translational energy of incident atom, crystalline structures of Bi_2Te_3 films and Bi, Te films, which are deposited on (001) NaCl, (001) MgO and glass by the vacuum deposition method with a Hostettler-Bernstien velocity selector, have been investigated by measurement thermoelectric power of film and the observation by a transmission electron microscopy. Thin films are affected by not only substrate temperature but also velocity of incident atoms greatly. We could obtain good thermoelectric element when we made films at a certain substrate temperature with velocity selector. However we could not clarify the effect of incident frequency on the deposition process, because it is difficult to conduct experiments at the high incident frequency with a velocity selector. Thus a molecular dynamics simulation has been performed to investigate the effects of incident velocity, substrate temperature and frequency of incident on the condensation phenomena in the deposition process of Kr atoms on Ar substrate. Substrate temperature and velocity of incident atom are affect the growth rate of nucleation and reevaporation of deposited atoms. Further those affect the structure of deposited film in the simulation. At high substrate temperature structure of thin film is broken, however at a certain substrate temperature, small incident velocity and low incident frequency, crystals grow with characteristic anisotropy on the substrate.