University of Northern Iowa, Physics, Cedar Falls, IA 50614
We have discovered that three dimensional topographical nanostructures form after exposing certain layered materials to high energy electrons using a scanning electron microscope (SEM). Intuitively, this exposure would damage the material and cause the exposed area to have material ejected from it. This would be measureable in an atomic force microscope (AFM) as a depression in the exposed area compared to the surrounding area. However, it was found that high energy electron exposure causes raised structures to form on the substrate in the exposed area. Using energy dispersive x-ray spectroscopy (EDX) these structures were found to be of similar chemical composition as the underlying substrate and seem to not be of foreign origin. High energy electron exposure has been performed on TiS2, TiSe2, ZrSe2, HfSe2, Bi2Se3, Bi2Te3, FeTe0.65Se0.35, Bi2Sr2CaCu2O8+x, HOPG, and Silicon. It produced three dimensional structures on every sample except Silicon, which is also the only material in the group that is not layered. Thus it has worked on every layered material we have tried. The potential applications for these nanostructures could influence fields varying from quantum computing to superconductivity.
[Abstract (DOCX)]