1. Materials Science and Engineering Program and Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, NY 13902, USA.
2. Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA.
3. Department of Electrical and Computer Engineering, State University of New York at Binghamton, Binghamton, NY 13902, USA.
4. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA.