1. Z. F. Ren, Z. P. Huang, J. W. Xu, J. H. Wang, Materials Synthesis Laboratory, Natural Sciences Complex, Departments of Physics and Chemistry, and Center for Advanced Photonic and Electronic Materials, State University of New York, Buffalo, NY 14260–3000, USA. P. Bush, Instrumentation Center, State University of New York, Buffalo, NY 14214, USA. M. P. Siegal and P. N. Provencio, Sandia National Laboratories, Albuquerque, NM 87185–1421, USA.