1. Department
of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
2. Department
of Physics, Cornell University, Ithaca, New York 14853, United States
3. Science & Technology Division, Corning Incorporated, SP-AR-02-4, Corning, New York 14830, United States
4. Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
5. Cornell
High Energy Synchrotron Source, Cornell University, Ithaca, New York 14850, United States