1. U.S. Naval Research Laboratory, Multifunctional Materials Branch, Washington, DC 20375, USA
2. Thomas Jefferson High School for Science and Technology, Alexandria, Virginia 22312, USA
3. National Research Council Postdoctoral Associate at the U. S. Naval Research Laboratory, Multifunctional Materials Branch, Washington, DC 20375, USA
4. Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA