[1] Dept. of Mat. Sci. and Engineering, University of Florida, Gainesville, FL 32611, United States
[2] Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, United States
[3] Department of Mechanical Engineering, National Central University, Chung-Li, Taiwan
[4] Department of Physics, National Central University, Chung-Li, Taiwan
[5] Sandia National Laboratory, Albuquerque, NM 87185, United States
[6] Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, United States