Speaker: Michael J. Aziz, Gordon McKay Professor of Materials Science, Harvard
Date & Time: March 30, 2006 - 1:30pm
Location: 260 Chemistry
Nanoscale Morphology Control using Ion Beams with Applications in Materials and Life Sciences
Laboratory for Surface Modification
Michael J. Aziz, Gordon McKay Professor of Materials Science, Harvard
1:30pm, 260 Chemistry
Low energy ion irradiation of a solid surface can be used to control surface morphology on length scales from 1 micron to 1 nanometer. Focused or unfocused ion irradiation induces a spontaneous self-organization of the surface into nanometer-sized ripples, dots, or holes; it also induces diameter increases and decreases in a pre-existing nanopore by a tradeoff between sputter removal of material and stimulated surface mass transport. Experiments will be reviewed that illuminate the kinetics of evolution of the surface morphological instability; the influence of initial and boundary conditions on guiding the self-organization; the development of shock fronts that sharpen features at sufficiently steep angles; and the kinetics governing the fabrication of nanopores for single-biomolecule detectors.