Physics Colloquium: Atomic structure and structural relaxation in amorphous Si and Ge

Event Details

  • Speaker(s): Sjoerd Roorda
  • Date:
  • Time: 3:30 PM
  • Location: MacN 101

Abstract:

The atomic structure of pure amorphous Si and Ge is believed to be that of a continuous random network with a local structure similar to that of the corresponding crystalline phase. I will show how we make high-purity samples of these materials and present high resolution (synchrotron) x-ray measurements and an interpretation in terms of atomic ordering and disordering on a length scale between 0.2 and 2 nm. Recently, the "paracrystalline" model of a-Si has re-emerged and our measurements show that such a model is not compatible with observation.

Host:

Professor Stefan Kycia