权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

In Situ Scanning Tunneling Microscopy for Analysis of Surface

用于表面分析的原位扫描隧道显微镜

基本信息

批准号：
63850160
负责人：
ITAYA Kingo
金额：
$ 4.1万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

We have constructed a scanning tunneling microscope(STM) for operation in electrochemical conditions in electrolyte solutions. The electrochemical potentials of the tunneling tip and the substrate with respect to a reference electrode can be simultaneously controlled. The apparatus offers a new possibility for complete. in situ observation of electrode surfaces in electrolyte solutions under potentiostatic conditions. The electrochemical deposition and dissolution of Ag have been investigated with this instrument.In situ STM was applied to single-crystal platinum(111) surfaces both before and after electrochemical potential cycling in an aqueous sulfuric acid solution. Steps observed on a Pt(111)facet were usually located on nearly parallel straight lines or on the directions forming an angle of close to 60ﾟ, as expected for a surface with threefold symmetry. The height of each step was in accord with the monatomic step height of 0.238nm on the Pt(111) surface. Randomly oriented islands a few atoms in height were clearly observed on the terraces after five potential cyclings. It was suggested that Pt adatoms produced by the reduction of the oxide are coagulated on the terraces.The topography and the surface electronic structure of various semiconductor electrodes have been examined in aqueous solutions by means of STM. It is shown, for example, that hydrogen-terminated Si surface are resistant to oxidation even in aqueous solutions. The tunneling current-electrode potential(I- E)curve suggests the existence of surface states. STM images of photoelectrochemically oxidized surfaces have been obtained.

我们建造了一台扫描隧道显微镜（STM），用于在电解质溶液中的电化学条件下操作。可以同时控制隧穿尖端和衬底相对于参考电极的电化学电势。该装置为全自动化生产提供了新的可能性。在恒电位条件下电解质溶液中的电极表面的原位观察。利用该仪器研究了Ag的电化学沉积和溶解过程，并在Pt（111）表面进行了原位扫描隧道显微镜（STM）观察。在Pt（111）面上观察到的台阶通常位于几乎平行的直线上或形成接近60 °角的方向上，正如对三重对称表面的预期。每个台阶的高度与Pt（111）表面的单原子台阶高度0.238nm一致雅阁。在五次潜在的循环之后，在阶地上清楚地观察到了几个原子高的随机取向的岛。用扫描隧道显微镜（STM）研究了各种半导体电极在水溶液中的形貌和表面电子结构。它示出，例如，氢封端的Si表面即使在水溶液中也抗氧化。隧穿电流-电极电位曲线表明表面态的存在。获得了光电化学氧化表面的STM图像。