Ultrasharp Single-Atom Tips Could Improve Microscopy

[nanoorg]

Ultrasharp Single-Atom Tips Could Improve Microscopy


New ultrasharp, single-atom tips created through a unique process could improve electron microscopy to a level that would make solutions possible to research problems currently just out of reach, its developers said.

Scientists from the University of Alberta (U of A), working out of the National Institute of Nanotechnology (NINT) at the university, used a unique process to make the sharpest tip ever known and opened the door to a range of possibilities, they said. They were able to coat peripheral atoms near the peak with nitrogen, making it a one-atom-thick, tough protective paint job.

"That coating has the effect of binding the little pyramid of metal atoms, or tungsten, in place," said Robert Wolkow, a physics professor at the U of A and co-author on the research paper published in the Journal of Chemical Physics. "Such a pointy pyramid of metal atoms would normally just smudge away spontaneously. It's like a sand pile -- you know you can't make it arbitrarily pointy. If you try to pile on more sand, it flows down and makes a more blunt pile. Metal atoms will do the same thing."

These sharp tips are needed for making contact with metals or semiconductors as well as for the manipulation and examination of atoms, molecules and small particles. Ultrafine tips are demanded for future experiments where the results are directly dependent on shape of the tip, he said.



Source:

http://www.photonics.com/


This story was first posted on 13th July 2006.