[1] Univ Houston, Dept Elect & Comp Engn, Houston, TX 77204 USA
[2] Univ Houston, Mat Sci & Engn Program, Houston, TX 77204 USA
[3] Univ Houston, Dept Phys, Houston, TX 77204 USA
[4] Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA
[5] Wuhan Univ Technol, State Key Lab Adv Technol Mat Synth & Proc, Wuhan 430070, Peoples R China