Abstract

Michael J. Aziz
Gordon McKay Professor of Materials Science
Division of Engineering and Applied Sciences
Harvard University

 

March 12, 2007
3:30- 4:30pm
MEC Rm. 341

 

"Nanoscale Morphology Control using Ion Beams with Applications in Materials and Life Sciences"

 

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.