1. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
2. Department of Materials Science and Engineering, Stony Brook University, Stony Brook, New York 11794, USA
3. Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
4. Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA