1. a Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research , Xi’an Jiaotong University , Xi’an , 710049 , P. R. China
2. b Department of Physics and Astronomy , University of Texas at San Antonio , San Antonio , TX , 78249
3. c The Texas Center for Superconductivity , University of Houston , Houston , TX , 77204
4. d Department of Material Science and Engineering , University of Texas at Arlington , Arlington , TX , 76019
5. e Department of Electrical and Computer Engineering , University of Texas at San Antonio , San Antonio , TX , 78249