1. Department of Printed Electronics Engineering; Sunchon National University; Jeonnam 57922 Korea
2. Department of Mechanical Engineering and Texas Center for Superconductivity at UH (TcSUH); University of Houston; Houston TX 77204-4006 USA
3. Department of Physics; Chungnam National University; Daejeon 34134 Korea
4. Materials Science and Engineering Program; University of Houston; Houston TX 77204 USA