With support from the Major Research Instrumentation MRI) Program, the Department of Chemistry at Columbia University will acquire a fully cryogenic scanning tunneling microscope (STM). This equipment will enhance research in a number of areas including a) local probing of reaction intermediates; b) structure, electronic properties and interactions of self-assembled monolayers; c) investigations of molecular charge transport; d) investigation and manipulation of a-dimensional nanostructures; and e) combining scanning tunneling microscopy and optical excitation/emission.
Scanning tunneling microscopy is a surface analytical technique that allows one to map out the atomic contours of a conducting surface. A metallic tip, sharpened to a single atom point, is brought very close to the surface of a conducting material. If a small voltage is applied to the tip, and the tip is brought very close to the surface, a current flows across the gap between the tip and surface. Since the magnitude of this tunneling currect is a function of the gap distance, if one measures the current as the tip moves across the surface, atomic information of the surface can be determined. STM is an extremely powerful tool for studying metal and semiconductor surfaces.
