NSF PR 03-31 - March 20, 2003
Two silicon nanoparticles with approximately 70-nm radii imaged by transmission electron microscopy (TEM) by Chris Perrey in Professor Barry Carter's research group at the University of Minnesota. Similar particles and much smaller were evaluated mechanically by graduate student Bill Mook in Professor William Gerberich's group. The nanosphere on the left is relatively defect free while the one at the right has a "nanotwin" from left to right. Defect-free nanospheres were found to be much harder than bulk silicon. (The inserts are electron diffraction patterns to determine crystallographic orientation.)
Credit: C. Perrey, C.B. Carter, University of Minnesota
TIFF of Photo 1 (851KB)
A 12-nm diameter silicon nanosphere, deformed by 2.3 nanometers in an atomistic simulation conducted by Mike Baskes of Los Alamos National Laboratory. At the top and the bottom the atoms are transformed into an amorphous state with no dislocations detected. Such simulations supported the hardness results measured experimentally by Bill Gerberich's team at Minnesota.
Credit: M.I. Baskes, Los Alamos National Laboratory
TIFF of Photo 2 (687KB)