在氟(F)摻雜之鐵基超導體(LaO1-xFxFeAs) 擁有超導轉變溫度26 K發現後，鐵基超導體的超導轉變溫度迅速被提升到56 K。硒化鐵擁有超導轉變溫度8 K且其結構在鐵基超導體中最為簡單。因此對於了解高溫超導體的超導機制，將可以提供重要的訊息，特別在於結構與超導之間的關係。在此論文中，我們將呈現{硒,碲}化鐵超導薄膜的傳輸性質，包括:霍爾效應，磁阻，和於超導態下之電流-電壓特性。對於低碲取代的薄膜，超導溫度受到明顯抑制。我們發現此抑制和低溫結構轉變有密切關聯。 霍爾係數有著強烈的溫度相依關係而可以利用簡單的二導帶模型(two-band model)加以分析和解釋。磁阻隨著碲取代量增加從正磁阻慢慢變為負磁阻。結合電阻率和霍爾效應行為，我們的結果指出負磁阻效應是來自於弱局域效應(weak localization effect)。另外，我們利用於超導態下之電流-電壓特性來研究磁通渦旋的行為。在高碲取代的樣品中，我們觀察到磁通渦旋之相轉變，從渦旋液態轉成渦旋玻璃態。而電流-電壓特性於渦旋玻璃態下亦可以被渦旋玻璃態模型所解釋。

Soon after the discovery of LaO1-xFxFeAs with Tc ~26 K, the TC of iron-based superconductor was quickly increased up to 56 K. FeSe1-x, having the simplest crystal structure among iron based superconductors, was reported with superconducting transition around 8 K. The simple structure of FeSe-superconductors might provide important clues to the mechanism of superconductivity in iron-based superconductors. In this thesis, the transport properties of FeSe1-xTex films, including resistivity, Hall effect, magnetoresistance, and current-voltage (I-V) characteristics in superconducting state, will be presented. The Tc of FeSe1-xTex thin film is suppressed seriously in low substituted samples, which is found to be closely associated with the confinement of structural distortion at low temperature. The Hall coefficient of FeSe1-xTex thin films has strong temperature dependence and can be described by two-band model. The magnetoresistance evolves from positive to negative gradually as the Te substitution level increases. Combine with the resistivity and Hall effect results, the negative magnetoresistance in higher Te substituted samples is attributed to the weak localization effect. The vortex state of FeSe-superconductors was investigated with the I-V characteristics of FeSe1-xTex thin films. A vortex liquid-glass transition and the scaling properties of I-V curves were observed in higher Te substituted samples, indicating the existence of vortex-glass state.

[1] Yoichi Kamihara, Hidenori Hiramatsu, Masahiro Hirano, Ryuto Kawamura, Hiroshi Yanagi, Toshio Kamiya, and Hideo Hosono, J. Am. Chem. Soc. 128, 10012 (2008).
[2] Yoichi Kamihara, Takumi Watanabe, Masahiro Hirano, and Hideo Hosono, J. Am. Chem. Soc. 130, 3296 (2008).
[3] X. H. Chen, T. Wu, G. Wu, R. H. Liu, H. Chen, and D. F. Fang, Nature 453, 761 (2008).
[4] G. F. Chen, Z. Li, D. Wu, G. Li, W. Z. Hu, J. Dong, P. Zheng, J. L. Luo, and N. L. Wang, Phys. Rev. Lett. 100, 247002 (2008).
[5] Zhi-An Ren, Jie Yang, Wei Lu, Wei Yi, Xiao-Li Shen, Zheng-Cai Li, Guang-Can Che, Xiao-Li Dong, Li-Ling Sun, Fang Zhou, and Zhong-Xian Zhao, Europhys. Lett. 82, 57002 (2008).
[6] Ren Zhi-An, Lu Wei, Yang Jie, YI Wei, Shen Xiao-Li, Li Zheng-Cai, Che Guang-Can, Dong Xiao-Li, Sun Li-Ling, Zhou Fang, and Zhao Zhong-Xian, Chin. Phys. Lett. 25, 2215 (2008).
[7] J. Dong, H. J. Zhang, G. Xu, Z. Li, G. Li, W. Z. Hu, D. Wu, G. F. Chen, X. Dai, J. L. Luo, Z. Fang, and N. L. Wang, Europhys. Lett. 83, 27006 (2008).
[8] B. Lorenz, K. Sasmal, R.P. Chaudhury, X.H. Chen, R.H. Liu, T. Wu, and C.W. Chu, Phys. Rev. B 78 , 012505 (2008).
[9] Jun Zhao, Q. Huang, Clarina De La Cruz, Shiliang Li, J. W. Lynn, Y. Chen, M. A. Green, G. F. Chen, G. Li, Z. Li, J. L. Luo, N. L. Wang, and Pengcheng Dai, Nature Mat. 7,953 (2008).
[10] H. Chen, Y. Ren, Y. Qiu, Wei Bao, R. H. Liu, G. Wu, T. Wu, Y. L. Xie, X. F. Wang, Q. Huang and X. H. Chen, Europhys. Lett. 85, 17006 (2009).
[11] D. J. Singh and M.-H. Du, Phys. Rev. Lett 100, 237003 (2008).
[12] K. Haule, J. H. Shim, and G. Kotliar, Phys. Rev. Lett 100, 226402 (2008).
[13] C. de la Cruz, Q. Huang, J.W. Lynn, J. Li, W. Ratcliff, H. A. Mook, G. F. Chen, J. L. Luo, N. L. Wang, and Pengcheng Dai, Nature (London) 453, 899 (2008).
[14] M. Rotter, M. Tegel, and D. Johrendt, Phys. Rev. Lett. 101,107006 (2008).
90
[15] J.H. Tapp, Z.J. Tang, B. Lv, K. Sasmal, B. Lorenz, C.W. Chu, and A.M. Guloy, Phys. Rev. B 78 , 060505(R), (2008).
[16] F.C. Hsu, J.Y. Luo, K.W. Yeh, T.K. Chen, T.W. Huang, P.M. Wu, Y.C. Lee, Y.L. Huang, Y.Y. Chu, D.C. Yan, and M.K. Wu, Proc. Natl. Acad. Sci. USA 105, 14262 (2008).
[17] C.W. Chu, B. Lorenz, Physica C 469, 477 (2009).
[18] M.H. Fang, H.M. Pham, B. Qian, T.J. Liu, E. K. Vehstedt, Y. Liu, L. Spinu, and Z. Q. Mao, Phys. Rev. B 78, 224503 (2008).
[19] K.W. Yeh, T.W. Huang, Y.L. Huang, T.K. Chen, F.C. Hsu, P.M. Wu, Y.C. Lee, Y.Y. Chu, C.L. Chen, J.Y. Luo, D.C. Yan, and M.K. Wu., Europhys. Lett. 84, 37002 (2008).
[20] Yoshikazu Mizuguchi Fumiaki Tomioka, Shunsuke Tsuda, Takahide Yamaguchi and Yoshihiko Takano,J. Phys. Soc. Jpn. 78, 074712 (2009).
[21] Y. Mizuguchi, F. Tomioka, S. Tsuda, T. Yamaguchi, and Y. Takano, Appl. Phys. Lett. 93, 152505 (2008).
[22] S. Medvedev, T. M. McQueen, I. A. Troyan, T. Palasyuk, M. I. Eremets, R. J. Cava, S. Naghavi, F. Casper, V. Ksenofontov, G.Wortmann and C. Felser, Nature Mater. 14, 2491 (2008).
[23] S. Margadonna, Y. Takabayashi, Y. Ohishi, Y. Mizuguchi, Y. Takano, T. Kagayama, T. Nakagawa, M. Takata, and K. Prassides, Phys. Rev. B 80, 064506 (2009).
[24] Alaska Subedi, Lijun Zhang, D.J. Singh, and M.H. Du, Phys. Rev. B 78, 134514 (2008).
[25] R. Khasanov, K. Conder, E. Pomjakushina, A. Amato, C. Baines, Z. Bukowski, J. Karpinski, S. Katrych, H.-H. Klauss, and H. Luetkens, Phys. Rev. B 78, 220510 (2008).
[26] H. Kotegawa, S. Masaki, Y. Awai, H. Tou, Y. Mizuguchi, and Y. Takano, J. Phys. Soc. Jpn. 77, 113703 (2008).
[27] T. Imai, K. Ahilan, F. L. Ning, T. M. McQueen, and R. J. Cava, Phys. Rev. Lett. 102, 177005 (2009).
91
[28] T. M. McQueen, Q. Huang, V. Ksenofontov, C. Felser, Q. Xu, H. Zandbergen, Y. S. Hor, J. Allred, A. J. Williams,D. Qu, J. Checkelsky, N. P. Ong, and R. J. Cava, Phys. Rev. B 79, 014522 (2009).
[29] B. C. Sales, A. S. Sefat, M. A. McGuire, R. Y. Jin, and D. Mandrus, Phys. Rev. B 79, 094521 (2009).
[30] T. J. Liu, X. Ke, B. Qian, J. Hu, D. Fobes, E. K. Vehstedt, H. Pham, J. H. Yang, M. H. Fang, L. Spinu, P. Schiffer, Y. Liu, and Z. Q. Mao, Phys. Rev. B 80, 174509 (2009).
[31] Jinsheng Wen, Guangyong Xu, Zhijun Xu, Zhi Wei Lin, Qiang Li, W. Ratcliff, Genda Gu, and J. M. Tranquada, Phys. Rev. B 80, 104506 (2009).
[32] R. Khasanov, M. Bendele, A. Amato, Babkevich, A. T. Boothroyd, A. Cervellino, K. Conder, S. N. Gvasaliya, H. Keller, H.-H. Klauss, H. Luetkens, V. Pomjakushin, E. Pomjakushina, and B. Roessli, Phys. Rev. B 80, 140511(R) (2009).
[33] C. Fang, B. A. Bernevig, and J. Hu, Europhys. Lett. 86, 67005 (2009).
[34] W. Bao, Y. Qiu, Q. Huang, M. A. Green, P. Zajdel, M. R. Fitzsimmons, M. Zhernenkov, S. Chang, M. Fang, B. Qian, E. K. Vehstedt, J. Yang, H. M. Pham, L. Spinu, and Z. Q. Mao, Phys. Rev. Lett. 102, 247001 (2009).
[35] Lijun Zhang, D. J. Singh, and M. H. Du, Phys. Rev. B 79, 012506 (2009).
[36] Chul-Ho Lee, Akira Iyo, Hiroshi Eisaki, Hijiri Kito, Maria Teresa Fernandez-Diaz, Toshimitsu Ito, Kunihiro Kihou, Hirofumi Matsuhata, Markus Braden, and Kazuyoshi Yamada, J. Phys. Soc. Jpn.77, 083704 (2008).
[37] Marianne Rotter, Michael Pangerl, Marcus Tegel, and Dirk Johrendt, Angew. Chem. Int. Ed. 47, 7949 (2008).
[38] Michael J. Pitcher, Dinah R. Parker, Paul Adamson, Sebastian J. C. Herkelrath, Andrew T. Boothroyd, and Simon J. Clarke, Chem. Commun. (Cambridge), 5918 (2008).
[39] K.W. Yeh, H.C. Hsu, T.W. Huang, P.M. Wu, Y.L. Huang, T.K. Chen, J.Y. Luo, and M.K. Wu, J. Phys. Soc. Jpn. Phys. 77, Suppl. C, 19 (2008).
92
[40] K.W. Yeh, C.T. Ke, T.W. Huang, T.K. Chen, Y.L. Huang, P.M. Wu and M.K. Wu, Cryst. Growth Des. 9, 4847 (2009).
[41] B.D. Cullity and S.R. Stock, Elements of X-ray diffraction (Prentice Hall, 3rd edition, 2001).
[42] C. Kittle, Introduction to solid state physics (John Wiley & Sons. Inc. ,New York, 7th edition, 1996).
[43] J.S. Dugdale, The electrical properties of disorder metals (Cambridge University, 1995).
[44] Y. Xia, D. Qian, L. Wray, D. Hsieh, G. F. Chen, J. L. Luo, N. L. Wang, and M. Z. Hasan, Phys. Rev. Lett. 103, 037002 (2009).
[45] N.P. Ong, Phys. Rev. B 18, 5272 (1978).
[46] J.M. Ziman, Principles of the theory of solid, (Cambridge University, Cambridge, England, 1964).
[47] B.L. Al’tshulter, A.G. Aronov, A.I. Larkin, and D.E. Khmel’nitskil, Sov. Phys. JETP 54. 411(1981).
[48] H. Fukuyama and K. Hoshino, J. Phys. Soc. Jpn. 50, 2131 (1981).
[49] David V. Baxter et al., J. Phys. France 50, 1673 (1989).
[50] A.I. Larkin et al., JETP Lett. 31,219 (1980).
[51] A. Stolovits and A. Sherman, Phys. Rev. B 71, 144519 (2005).
[52] Prabhakar P. Singh, arXiv: 0908.0303.
[53] See, e.g., Electrons and Phonons, edited by J. M. Ziman (Clarendon, London, 1963), p. 492.
[54] C.Y. Wu and J.J. Lin, Phys. Rev. B 50, 385(1994).
[55] I. I. Mazin and M. D. Johannes, Nature Phys. 5, 141 (2009).
[56] R. Meservey R and P.M. Tedrow, Phys. Rev. Lett. 41, 805 (1978).
93
[57] Ralph Rosenbaum, Phys. Rev. B 32, 2190 (1985).
[58] M. T. Beal-Monod and R. A. Weiner, Phys. Rev. 170, 552 (1968).
[59] M. Tinkham, Introduction to superconductivity (Dover, New York, 2nd edition, 2004).
[60] A.A. Abrikosov and Zh. Eksperim, Sov. Phys. JETP 5, 1174 (1957).
[61] G. Blatter, M. V. Feigel’man, V. B. Geshkenbein, A. I. Larkin, and V. M. Vinokur, Rev. Mod. Phys. 66, 1125 (1994).
[62] A. I. Larkin and Yu. V. Ovchinnikov, J. Low. Temp. Phys. 34, 409 (1979).
[63] M. P. A. Fisher, Phys. Rev. Lett. 62, 1415 (1989).
[64] D. S. Fisher, M. P. A. Fisher, and D. A. Huse, Phys. Rev. B 43, 130 (1991).
[65] R. H. Koch, V. Foglietti, W. J. Gallagher, G. Koren, A. Gupta, and M. P. A. Fisher, Phys. Rev. Lett. 63, 1511 (1989).
[66] M. O. Mun, S. I. Lee, W. C. Lee, P. C. Canfield, B. K. Cho, and D. C. Johnston, Phys. Rev. Lett. 76, 2790 (1996).
[67] Hyeong-Jin Kim, W. N. Kang, Eun-Mi Choi, Mun-Seog. Kim, Kijoon H. P. Kim, and Sung-Ik Lee, Phys. Rev. Lett. 87, 087002 (2001).
[68] Hyeong-Jin Kim, Yong Liu, Yoon Seok Oh, Seunghyun Khim, Ingyu Kim, G. R. Stewart, and Kee Hoon Kim, Phys. Rev. B 79, 014514 (2009).
[69] P. W. Anderson, Phys. Rev. Lett. 9, 309 (1962); P. W. Anderson and Y. B. Kim, Rev. Mod. Phys. 36, 39 (1964).
[70] T. T. M. Palstra, B. Batlogg, R. B. van Dover, L. F. Schneemyer, and J. V. Waszczak, Phys. Rev. B 41, 6621 (1990).
[71] J. B. Ketterson and S. N. Song, Superconductivity, (Cambridge university press, New York, 1999).
[72] Hechang Lei, Rongwei Hu, E. S. Choi, J. B. Warren, and C. Petrovic, arXiv: 1001.1751.
94
[73] Werthamer N R, Helfand E, and Hohenberg P C, Phys. Rev. 147, 295 (1966).