Investigating Atoms and Structures using Scanning Tunneling Microscopy (STM)

2003 Summer Research Student: Matt Stackpole (physics)

A very powerful and convincing demonstration of our ability to do nanoscale science is to see a scanning tunneling microscope (STM) collecting images of atoms on a surface. The purchase of a fully portable Nanosurf® easyScan E Scanning Tunneling Microscope (NES-STM) system and laptop will allow us to demonstrate and experiment with atomic imaging with a wide variety of audiences. The NES-STM is a compact, portable, safe instrument with straightforward operating procedures including tip preparation, sample mounting and image collecting. The instrument design includes sufficient vibrational isolation so images are clear and atomic resolution can be obtained. The open design of the instrument makes changing tips and samples simple and fast. Using the NES-STM this laboratory will introduce students to the concept of quantum tunneling and how it is the key to the STM's ability to image atoms on a surface. Students will use the NES-STM to image features of single crystal graphite, Figure 1a, and other surfaces such as plated gold. In addition, gold nanoparticles (see 1b) can be imaged in connection with the experiments The Preparation of Gold Nanoparticles and A Colorimetric Pb(II) Sensor Based on a Au-nanoparticle, DNA-zyme System.[3]

Figure 1(a) An STM image of a single crystal graphite surface showing atomic resolution of carbon atoms. 1(b) An STM image of ~ 15 nm gold nanoparticles dispersed on a mica substrate.

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Last updated February , 2006

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