1. Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States
2. Texas Center for Superconductivity (TcSUH) and Department of Physics, University of Houston, Houston, Texas 77204, United States
3. Department of Chemistry, University of Houston, Houston, Texas 77204, United States
4. Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, United States