1. Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, United States
2. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. Center for Spinelectronic Materials and Devices, Physics Department, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
4. Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, United States
5. Department of Materials Science and Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
6. Cornell High Energy Synchrotron Source, Ithaca, New York 14853, United States