1. Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA
2. Department of Electrical and Computer Engineering, University of Alabama, Tuscaloosa, Alabama 35487, USA
3. Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA
4. Department of Metallurgical and Materials Engineering, University of Alabama, Tuscaloosa, Alabama 35487, USA
5. National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8552, USA