臺灣博碩士論文加值系統

我們分析混合態之縱向電阻率ρxx及橫向電阻率ρxy，藉以探討具有人工釘扎反點(洞)陣列之高溫超導YBa2Cu3Oy (YBCO)薄膜之磁通釘扎效應。利用電子束微影技術，在20 μm × 20 μm之微橋上製作出不同長寬比例之人工釘扎反點(洞)陣列(短軸a：長軸b = 1 μm：1.6 μm)，並將外加電流平行於a軸及b軸方向，量測其縱向電阻率ρxx、橫向電阻率ρxy、活化能(activation energy)U及霍爾係數RH。
當電流平行於a軸時，我們發現霍爾係數RH之反正行為(Sign reversal)及活化能U較小，這表示磁通渦流運動對不規則之霍爾效應以及磁通釘扎效應對RH之反正行為有極大的相關性。另外，縱向電阻率ρxx及橫向電阻率ρxy之關係式ρxy~ρxxβ，其冪次關係β值隨磁場降低而變小。此實驗結果可以磁通渦流動力學討論之。

The mixed-state longitudinal (ρxx) and transverse (ρxy) resistivities were examined in order to study the effect of flux pinning in a YBa2Cu3Oy (YBCO) thin films with an artificial anti-dot lattice. The antidotes were arranged in a rectangular array with lattices parameters of a = 1 μm and b = 1.6 μm, and extend over 20 μm × 20 μm areas by e-beam lithography process. The activation energy U, ρxx , Hall coefficient RH, and ρxy were measured with currents applied along the a-axis and b-axis directions of the rectangular array, respectively. It was observed that the sign reversal of the Hall coefficient RH diminishes within the measured configuration with current applied along the a axis of the rectangular array, accompanying an observed decrease of U. This implies that the mechanism of flux flow may be the most important origin of the anomalous Hall effect and the sign reversal of RH is sensitive to the flux pinning. In addition, the exponent β in scaling behavior ρxy~ρxxβ is magnetic field dependent and becomes smaller when the current is applied along the a axis of the rectangular array. The experimental results are discussed within the framework of vortex-dynamics theories.

封面內頁
簽名頁
授權書 ．．．．．．．．．．．．．．．．．．．．．．iii
中文摘要 ．．．．．．．．．．．．．．．．．．．．．iv
英文摘要 ．．．．．．．．．．．．．．．．．．．．．．v
誌謝 ．．．．．．．．．．．．．．．．．．．．．．．vi
目錄 ．．．．．．．．．．．．．．．．．．．．．．．vii
圖目錄 ．．．．．．．．．．．．．．．．．．．．．．．x
表目錄 ．．．．．．．．．．．．．．．．．．．．．．xiv

第一章 緒論
1.1 研究背景 ．．．．．．．．．．．．．．．．．．．．1
1.1.1 混合態霍爾效應與磁通釘扎．．．．．．．．．．1
1.1.2 霍爾效應的反正行為(Sign Reversal) ．．．．．．4
1.1.3 人通磁通釘扎．．．．．．．．．．．．．．．．7
1.2 研究動機．．．．．．．．．．．．．．．．．．．．10
第二章 基本原理
2.1 超導體磁性質．．．．．．．．．．．．．．．．．．12
2.1.1 第一類超導體 ．．．．．．．．．．．．．．．13
2.2.2 第二類超導體 ．．．．．．．．．．．．．．．13
2.2 混合態的磁通漩渦線．．．．．．．．．．．．．．．14
2.3 非理想的第二類超導體與磁通釘扎．．．．．．．．．16
2.4 理想的磁通流動(Flux flow) ．．．．．．．．．．．．18
2.5 Anderson-Kim磁通蠕動模型 ．．．．．．．．．．．21
2.6 霍爾電阻率與縱向電阻率 關係式．．．．．．25
第三章 實驗方法與儀器設備
3.1 前言．．．．．．．．．．．．．．．．．．．．．．26
3.2 實驗儀器．．．．．．．．．．．．．．．．．．．．27
3.2.1 薄膜濺鍍系統 ．．．．．．．．．．．．．．．27
3.2.2 熱蒸鍍系統 ．．．．．．．．．．．．．．．．30
3.2.3 掃描電子顯微鏡之應用 ．．．．．．．．．．．31
3.2.4 Ar離子蝕刻．．．．．．．．．．．．．．．．34
3.2.5 霍爾量測系統-超導量子干涉儀．．．．．．．．37
3.2.6 原子力顯微鏡(AFM) ．．．．．．．．．．．．38
3.3 樣品製程與量測．．．．．．．．．．．．．．．．．40
3.3.1 樣品製程 ．．．．．．．．．．．．．．．．．40
3.3.2 樣品分析與量測 ．．．．．．．．．．．．．．51
第四章 結果與討論
4.1 利用電子束微影技術之不對稱比例(1:1.6)人工釘扎反點(洞)陣列之特性探討．．．．．．．．．．．．．．．56
4.1.1 樣品Hall6ab之縱向電阻率ρxx特性討論．．．．56
4.1.2 樣品Hall6ab之釘扎位能U之討論 ．．．．．．58
4.1.3 樣品Hall6ab之霍爾係數RH之討論．．．．．．64
4.1.4 樣品Hall6ab之縱向電阻率ρxx及霍爾電阻率ρxy之冪次關係β ．．．．．．．．．．．．．．．．68
4.2 利用黃光微影技術之人工釘扎鎳點陣列之特性討論．．71
4.2.1樣品M20dot之縱向電阻率ρxx特性討論 ．．．．71
4.2.2樣品M20dot之釘扎位能U之討論．．．．．．．72
4.2.3樣品M20dot之霍爾係數RH之討論 ．．．．．．75
4.2.4樣品M20dot之縱向電阻率ρxx及霍爾電阻率ρxy之冪次關係β ．．．．．．．．．．．．．．．．．77
第五章 結論 ．．．．．．．．．．．．．．．．．．．．．80
參考文獻 ．．．．．．．．．．．．．．．．．．．．．．．82

[1]Y. Iye, S. Nakamura, and T. Tanegai, Physica (Amsterdam) 159 C, 616 (1989).
[2]K.C.Woo, K.E.Gray, R.T.Kampurith, and J.H.Kang,Physica 162C-164C, 1011 (1989).
[3]T.Tamegic and Y.Iye,Phys. Rev. B 44, 10167 (1991).(Amsterdam)
[4]N. P. Ong et al., Physica (Amsterdam) 185C, 34 (1991).
[5]Z. V. Zavarisky, A. V. Samoilov, and A. A. Yurgens, Physica (Amsterdam) 180C, 417 (1991).
[6]I.Puica, W.Land, W.Gob and Roman Sobolewski, Phys. Rev. B 69, 104513 (2004).
[7]A.G.Arrov and S. H. Kami, Phys. Rev. B 41, 9548 (1990).
[8]J. E. Hirsch and F. Marsiglo, Phys. Rev. B 43, 424 (1991).
[9]L. Lu, Ph.D. dissertation, Beijing University, China, 1992.
[10]A. Freimuth, C. Hohn, and M. Galffy, Phys. Rev. B 44, 10396 (1991).
[11]J.L.Chen and T.J. Yang, Phys.Rev. B 50, 4064 (1994).
[12]Y.X.Jia, T.Z.Liu, M.D.Lau, and R.N.Shelton, phys. Rev. B 47, 6043 (1993).
[13]E.Z.Meilikhov and R.M.Farzetdinova. Physica (Amsterdam) 210C, 473 (1993).
[14]Z.D.Wang and C.S.Ting, Phys. Rev. B 46, 284 (1992).
[15]H. E. Horng et al., Solid State Commun. 93, 537 (1995).
[16]L.M. Wang, H.C. Yang, H.E. Horng, Phys. Rev. Lett.78, 527 (1997).
[17]W. N. Kang, S. H. Yun, J. Z. Wu D. and H. Kim, Phys. Rev. B 55, 621 (1997).
[18]J. Bardeen and M. J. Stefan, Phys. Rev. 140, A1197 (1965); J. Bardeen and M. J. Stefan, Phys. Rev. Lett. 14, 112 (1965).
[19]P. Nozieres and W. F. Vinen, Philos. Mag. 14,667 (1966).
[20]J. M. Harris, N. P. Ong, and Y. F. Yan, Phys. Rev.Lett.71,1455 (1993).B. D. Josephson, Phys. Lett. 16, 242 (1965).
[21]R. C. Budhani, S. H. Liou, and Z. X. Cai, Phys. Rev. Lett. 71,
621 (1993).
[22]S. Ullah and A.T. Dorsey, Phys. Rev. B 44, 262 (1991).
[23]A. T. Dorsey, Phys.Rev. B 46, 8376 (1992).
[24]R. J. Troy and A. T. Dorsey, Phys. Rev. B 47, 2715 (1993).
[25]N. B. Kopnin, B. I. Ivlev, and V. A. Kalatsky, J. Low. Temp. phys, 90, 1 (1993).
[26]W. Gob,1 W. Liebich, W. Lang, I. Puica, Roman Sobolewski, R. Rossler, J. D. Pedarnig, and D. Bauerle, Phys.Rev. B 62, 9780 (2000).
[27]N. B. Kopnin and V. M. Vinokur, Phys. Rev. Lett. 83, 4864 (1999).
[28]J.-Y. Lin, M. Gurvitch, S. K. Tolpygo, A. Bourdillon, S. Y. Hou and Julia M. Phillips, Phys.Rev. B 54, R12717 (1996).
[29]Yukio Yamamoto , Keiichi Ogawa, Physica C 371, 209 (2002).
[30]大葉大學，郭志謙，95碩士論文
[31]W. Meissner and R. Ochsenfeld, Naturwiss, 21(1933), 787.
[32]T. Nishizaki et al., Physica (Amsterdam) 181C, 223 (1991).
[33]超導電性導論p189-193，p137-153，P208-210
[34]P. W. Anderson, and Y. B. Kim, Rev. of Mod. Phys. (1964) 39.
[35]H.C. Yang, J.C. Chen, L.M. Wang, H.H. Sung, H.E.Horng, S.Y. Yang, J.T. Jeng, Journal of Physics and Chemistry of Solids 62, 1837 (2001)
[36] J. Luo, T.P. Orlando, J. M. Graybeal, X. D. Wu, and R. Muenchausen, Phys. Rev. Lett. 68, 690 (1992).
[37]A. V. Samoilov, Phys. Rev. Lett. 71,617 (1993).
[38]H.C. Yang, H.E. Horng, L.M. Wang, Chin. J. Phys. 36, 527 (1998)
[39]H.C Yang, L.M. Wang, H.E. Horng, Phys. Rev. B 56, 99(1997)
[40]L.M. Wang,H.W. Yu,H.C. Yang,H.E. Horng, Physica C 256.57-63. (1996)