掃描式穿隧電子顯微鏡——新腐蝕研究利器

Scanning Tunneling Microscope–A Powerful Tool for Corrosion Research

掃描式穿隧電子顯微鏡（STM）具超高解析能力，可觀測材料表面三軸立體排列情形達個別原子尺度，使表面科學研究領域及檢測技術邁進更新的紀元。現行一般表面分析儀器，如掃描式電子顯微鏡（SEM），光電子化學分析儀（ESCA），歐傑光譜儀（AES），二次離子質譜儀（SIMS）及低能量電子繞射儀（LEED）等，雖可提供給我們非常有價值的資訊，但在進行測試時都必須在高真空環境中方能運作。然使用STM能在空氣中甚至液體中檢測材料表面位像圖（Topography），而最具應用價值的是STM在腐蝕研究上，試樣表面可在電化學控制下同時進行表面研析，對開創材料研究技術有莫大助益。

Because of its ultrahigh resolution, the Scanning Tunneling Microscope (STM) can be used to image the topography of a surface down to atomic scale and also to make progress of the surface analysis technology to a new milestone. Although those widely used instruments of surface analysis such as scanning electron microscope (SEM), electron spectroscopy for chemical analysis (ESCA), Auger electron spectroscope (AES), secondary ion mass spectroscopy (SIMS) and low energy electron diffraction (LEED) can give us valuable informations, they should be operated in high vacuum environment. However, the STM can image the surface of solid electrode in air or even in liquid media. And the in-situ STM for real-time study on the rate of atomic dissolution is the most powerful technique in this field. In this investigation, A special electrochemical apparatus was designed and a coating technique of tip was developed for the study of the corrosion behavior of metal electrode by STM. Furthermore, the electrodes of lead-deposited on HOPG with atomically flat were also prepared for the study on the galvanic corrosion mechanism by STM.