June 5, 2009
Materials Science and Engineering Professor Katayun Barmak and Microscopy Lab Supervisor Thomas Nuhfer have become the first materials scientists worldwide to successfully map polycrystalline structures on a nanoscale. This mapping ability has come at the same time that Barmak and her colleagues found that physical properties of some structures change at the nanoscale.
Polycrystalline structures are made up of three-dimensional patterns of atoms, ions and molecules called crystals, which take on a range of orientations in space. These homogeneous solid crystallites — and the boundaries between them — are what Barmak is mapping. Her research, for example, shows that the minute grain boundaries of crystalline materials can obstruct the flow of an electric charge when subject to an electric field.
"Because we can now monitor these changes in structure and form at the nanoscale level, we can begin to see how metallic elements like copper can be tailored to be an even better conductive agent," said Barmak. "I can see major impacts from our work for a whole host of engineered systems that harness nanotechnology." She said some examples of those important systems include silicon chips and data storage systems, photovoltaics and fuel cells, and medical devices and drug delivery systems.
For the full press release about Barmak's mapping efforts, visit www.cmu.edu/news/archive/2009/June/june4_barmak.shtml.