1. Department of NanoEngineering, University of California San Diego, La Jolla, California 92093, United States
2. National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
3. Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
4. Program of Material Science, University of California San Diego, La Jolla, California 92093, United States
5. Center for Memory and Recording Research, University of California San Diego, La Jolla, California 92093, United States