Observing Nanscale Metallic Puddles And Mystery Behavior In Electrons

12-13-07

Observing Nanscale Metallic Puddles And Mystery Behavior In Electrons

www.sciencedaily.com

Sciencedaily, (2007), Observing Nanscale Metallic Puddles And Mystery Behavior In Electrons

      In collaboration with the Center for Integrated Nanotechnologies at Los Alamos, an international team of researchers has, for the first time, viewed on a nanoscale the formation of mysterious metallic puddles that facilitate the transition of an electrically insulating material into an electrically conducting one. The research may lead to a better understanding of superconductors–materials that conduct electricity without energy loss–or development of better materials for powering high-speed electronics.

     

      For decades scientists have puzzled over how this transformation to a fully metallic state–known as “Mott” metal-insulator transition–occurs. Balatsky, a Los Alamos condensed-matter theorist, believed, like many other scientists, that the transition begins when metallic puddles begin forming at sites of impurities or imperfections within the lattice. The puddles grow until they touch, and at that point the material becomes conductive, or superconductive.

“We had evidence to believe that metallic puddles were forming in an inhomogenous manner within the material at the transition phase, but we had no way of proving it,” said Balatsky. “If you had the right glasses that could see something extremely small, you could see this process occurring.”

      By reading this articl, I learned that people viewed on a nanoscale, the formation of mysterious metallic puddles that facilitate the transition of an electrically insulating material into an electrically conducting one

Catalyst-free Chemistry Makes Self-healing Materials More Practical

                      12-4-07

Catalyst-free Chemistry Makes Self-healing Materials More Practical

www.sciencedaily.com

ScienceDaily, (2007), Catalyst-free Chemistry Makes Self-healing Materials More Practical

      A new catalyst-free, self-healing material system developed by researchers at the University of Illinois offers a far less expensive and far more practical way to repair composite materials used in structural applications ranging from airplane fuselages to wind-farm propeller blades.

      The new self-healing system incorporates chlorobenzene microcapsules, as small as 150 microns in diameter, as an active solvent. The expensive, ruthenium-based Grubbs’ catalyst, which was required in the researchers’ first approach, is no longer needed. During normal use, epoxy-based materials experience stresses that can cause cracking, which can lead to mechanical failure. Autonomous self-healing — a process in which the damage itself triggers the repair mechanism — can retain structural integrity and extend the lifetime of the material.

      By reading this article, I learned that a new self-healing material has been developed. It offers a new way to repair composite materials used in structural applications.