1. Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA
2. Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
3. Sandia National Laboratories, Livermore, California 94550, USA
4. Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
5. Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124, USA
6. Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904, USA
7. Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA