Scanning tunnelling microscopy (STM) and transmission electron microscopy (TEM) are two well-known atomic imaging techniques. The combination of these two microscopies, deriving from the concepts of nano-eye in STM and nano-finger in TEM, provides in situ observation and measurement to accompany the growth and manipulation of nanostructures. For example, the above HRTEM picture (left), in comparison with the simulated scheme (right), depicts how the group uses the STM@TEM functionality to tailor an ultrasharp CNT apex to approach the dimensions of a single-walled CNT.

A key advantage of the team's set-up is that the entire experiment can be operated in a UHV chamber (< 3 x 10–10 mbar), which reduces the exposure of the manipulated nanostructures to contaminants. In addition, the synchronous control can eliminate unexpected damage that can occur during sample transfer.

In their recent paper, the researchers describe in detail how to fabricate CNT probes using the UHV technique and highlight the advantages of their approach compared with conventional methods. The prominent probe quality has routinely led to a good resolution in SPM measurements, such as <5 nm for AFM and <10 nm for EFM (see earlier work).

The group presented its work in Nanotechnology.