臺灣博碩士論文加值系統

本實驗經研磨、鍛燒、壓胚、燒結等傳統之粉末冶金程序，製作添加0at%〜10 at%MgO之La0.67MgxCa0.33MnO3、La0.67MgxSr0.33MnO3鈣鈦礦錳氧化物材料，並利用DC磁控濺鍍法，將薄膜成長於（100）Si基板上，藉由控制濺鍍壓力、退火溫度及添加不同MgO量，藉由Mg2+去取代部份Ca2+、Sr2+原子等實驗參數，進而探討其高溫及小磁場下之磁阻特性。而經由成分比例的改變，使改變其組織結構，再進行結晶結構及顯微組織之分析，觀察其磁阻的行為及半導體-金屬轉換溫度之變化。
經由實驗結果發現，在塊材中添加MgO會抑制LaCaMnO及LaSrMnO晶粒的成長，而使晶界量增多。且當MgO添加量增加到2 at%以上，塊材組織中之MgO的量會大幅增加，且析出物會在晶界上形成。當MgO量增加時，電阻係數有明顯上升的趨勢，其金屬半導體轉換溫度卻會隨MgO添加量增加而往低溫偏移。塊材之磁阻因MgO添加，可以大幅提高塊材磁阻比值。添加MgO於LSMO塊材中，其晶粒變化趨勢、MgO析出的情形、電阻係數的變化跟LaCaMnO塊材都非常類似，惟磁阻最大值只有46%。
由XRD實驗得知，LaCaMnO及LaSrMnO薄膜的結構為多晶組織，當MgO量增加時，電阻係數有明顯上升的趨勢，而磁阻則隨著MgO含量的增加而上升。而所有退火溫度又以1250K可以得到最好的磁阻比。所以初鍍膜在經1250K 持溫4小時熱處理後，MgO之La0.67MgxCa0.33MnO3、La0.67MgxSr0.33MnO3結晶形成，可以得到最大磁阻比為10258%。

In this work, the bulk samples of La0.67Ca0.33MgxMnO3 and La0.67Sr0.33MgxMnO3 with addition of 0% ~ 10% MgO were prepared by the traditional process of powder metallurgy. Stoichiometric mixtures of high-purity powder were grinded, calcinated, pressed into the bar samples, and then sintered. The thin films were deposited on Si (100) by magnetron sputtering. By change of sputtering pressure, annealing temperature and addition of MgO, the Mg2+ ion substites the Ca2+ or Sr2+ ion. We inrestigate their magnetoresistance behavior in the high temperature and low magnetic field.
By XRD result, the bulk microsturctures of La0.67Ca0.33MgxMnO3 and La0.67Sr0.33MgxMnO3 were polycrystalline. The grain size decreases as a result of MgO addition. The resistivities of La0.67Ca0.33MgxMnO3 and La0.67Sr0.33MgxMnO3 increase with the content of MgO. The effect of MgO addition on the structure and magneto-transport property of La0.67Ca0.33MgxMnO3 is similar to that of La0.67Sr0.33MgxMnO3. MgO increases, the magneto-transport temperature decreases. With addition of 10%MgO, the thin films deposited by pressure of 10 m torr and annealing temperature of 1250K enhance the magnetroresistance ratio up to 10258%.

目 錄
頁次
中文摘要 I
英文摘要 II
誌謝 III
目錄 IV
圖目錄 VII
表目錄 XII
第一章 緒論 1
1-1 前言 1
1-2 研究動機 2
第二章 理論基礎與文獻回顧 4
2-1 磁性理論 4
2-1-1 磁性物質的介紹 4
2-1-2 磁性物質的分類 4
2-2 晶格結構 8
2-3 特性相圖與磁阻特性 10
2-4 磁阻類別及種類 12
2-4-1 磁阻類別 12
2-4-2 磁阻材料的種類 13
2-5 超巨磁阻理論及相關理論 17
2-5-1 超巨磁阻介紹 17
2-5-2 雙交換互作用 20
2-5-3 John-Teller Effect 24
2-5-4 低磁場巨磁阻效應 25
2-6 磁雜質引起自旋反轉的影響 27
2-7 熱處理對磁阻特性的影響 28
2-8 晶界對磁阻特性的影響 29
2-9 點缺陷之效應 30
2-10 濺射理論 31
2-11 薄膜沈積機制原理 38
第三章 實驗方法及內容 42
3-1 塊材、靶材及薄膜的製備與量測 42
3-2 基板前處理 46
3-3 真空系統 46
3-4 基板加熱裝置 48
3-5 熱處理 48
3-6 塊材與薄膜特性量測與分析 49
3-6-1 膜厚量測 49
3-6-2 顯微結構及成份分析 50
3-6-3 磁阻量測流程 50
第四章 結果與討論 52
4-1 試片成分 52
4-2 La-Ca-Mg-Mn-O塊材 53
4-2-1 結晶構造與顯微組織 53
4-2-2 電阻係數與溫度的關係 56
4-2-3 磁阻比值與溫度的關係 57
4-3 La-Sr-Mg-Mn-O塊材 60
4-3-1 結晶構造與顯微組織 60
4-3-2 電阻係數與溫度的關係 63
4-3-3 磁阻比值與溫度的關係 64
4-4 熱處理之La-Ca-Mg-Mn-O薄膜 66
4-4-1 不同MgO添加量對薄膜結晶結構的影響 66
4-4-2 不同退火溫度對薄膜結晶結構的影響 67
4-4-3 不同濺鍍壓力對薄膜結晶結構的影響 69
4-4-4 添加2%MgO及5%MgO的La0.67Ca.33MnO3薄膜在不同濺鍍壓力的SEM微觀觀察 70
4-4-5 成分對La0.67Ca0.33MgxMnO3薄膜的電阻係數及磁阻比之影響 72
4-4-6 退火溫度對La0.67Ca0.33MgxMnO3薄膜的磁阻之影響 74
4-4-7 濺鍍壓力對La0.67Ca0.33MgxMnO3薄膜的磁阻之影響 75
4-5 熱處理之La-Sr-Mg-Mn-O薄膜 78
4-5-1 不同MgO添加量對薄膜結晶結構的影響 78
4-5-2 不同退火溫度對薄膜結晶結構的影響 79
4-5-3 不同濺鍍壓力對薄膜結晶結構的影響 81
4-5-4 添加2%MgO及5%MgO的La0.67Sr.33MnO3薄膜在不同濺鍍壓力的SEM微觀觀察 82
4-5-5 成分對La0.67Sr0.33MgxMnO3薄膜的電阻係數及磁阻比之影響 84
4-5-6 退火溫度對La0.67Sr0.33MgxMnO3薄膜的磁阻之影響 86
4-5-7 濺鍍壓力對La0.67Sr0.33MgxMnO3薄膜的磁阻之影響 88
第五章 結論 91

Reference
1. 陳至堯，“鑭-鈰-鈣-錳超巨磁阻氧化物的結構與磁有序特性探討”，碩士論文，中央大學物理所，2000年6月。
2. Soshin Chikazurni 著，張喣、李學養譯，磁性物理學，聯經出版社，1982年。
3. Charles Kittel, “Introduction to Solid State Physics,” 4th ed. Chap. 14-15, John Wiley & Sons. Inc., 1996.
4. Jonker G. H. and Van Santen J. H., “Interaction between the d-Shells in the Transition Metals. II. Ferromagnetic Compounds of Manganese with Perovskite Structure,” Physica, Vol. 16, pp. 337-342, 1950.
5. M. N. Baibich, J. M. Broto, A. Pert, P. Nguyen, P. Petroff, P. Etienne, G. Greuzet, A. Prienderich, and J. Chazelas, “Giant Magnetoresistance of (001)Fe/(001)Cr Magnetic Superlattices,” Phys. Rev. B61, pp. 2472-2476, 1988.
6. P. N. Santhosh, A. Arulraj, P. V. Vanitha, R. S. Singh, “Comment on Double-exchange ferromagnetism in La(Mn1-xCox)O3,” Phys. Rev. B61, pp. 2365-2368, 1988.
7. H. Y. Hwang, S. W. Cheong, P. G. Radaelli, M. Marezio, and B. Batlogg, “Lattice Effects on the Magnetoresistance in Doped LaMnO3,” phys. Rev. Lett. Vol. 75, pp. 914-916, 1995.
8. R. M. Thomas, V. Skumryev, J. M. D. Coey, S. Wirth, “High magnetic field studies of 3d and 4f magnetism in (R0.7A0.3)MnO3: R = La3 + , Pr3 + , Nd3 + , A = Ca2 + , Sr2 + , Ba2 + , Pb2 +,” J. Appl. Phys. Vol. 85, pp. 5384-5387, 1999.
9. S. Jin, T. H. Tiefel, M. McCormark, R. A. Fastnacht, R. Ramesh, L. H. Chen, “Thousandfold change in resistivity in magnetoresistive La-Ca-Mn-O,” SCIENCE, Vol. 264, pp. 413-415, 1994.
10. R. Maezono, S. Eshihara, N. Nagaosa, “Phase diagram of manganese oxides”, Phys. Rev. B58, pp. 11583-11585, 1998.
11. R. Mahendiran, S. K. Tiwary, A. K. Raychaudhuri, T. V. Ramakrishnan, “Structure, electron-transport properties, and giant magnetoresistance of hole-doped LaMnO3 systems,” Phys. Rev. B53, pp. 3348-3351, 1996.
12. M. Mccirnacj, “Magnetic-field-induced insulator-metal phenomena in perovskite manganese oxides,” J. Appl. Phys. Vol. 64, pp. 3045-3050, 1994.
13. G. C. Xiong, “Roles of orbital in magnetoelectronic properties of colossal magnetoresistive manganites,” J. Appl. Phys. Vol. 66, pp.1427-1434, 1950.
14. Z. W. Dong, “The complex magnetic behavior and the role of dynamic structural fluctuations in La1.2Sr1.8Mn2O7 crystals,” IEEE Tran. Appl. Superconduc. Vol. 7, pp.2173-2177, 1997.
15. M. F. Hundley, “Metal—insulator transition induced by 16O—18O oxygen isotope exchange in colossal negative magnetoresistance manganites,” Appl. Phys. Lett. Vol. 67, pp.860-866, 1995.
16. G. J. Snyder, R. Hiskes, S. DiCarolis, M. R. Beasley, and T. H. Geballe, “Intrinsic electrical transport and magnetic properties of La0.67Ca0.33MnO3 and La0.67Sr0.33MnO3 MOCVD thin films and bulk material,” Phys. Rev. B53, pp.53-57, 1996.
17. H. T. Hardner, M. B. Weissman, M. Jaime, R. E. Treece, P. C. Dorsey, J. S. Horwitz, and D. B. Chrisey, “Non-Gaussian noise in a colossal magnetoresistive film,” J. Appl. Phys., Vol. 81, pp.272-276, 1997.
18. A. P. Ramirez, “Structure and magnetoresistive properties in La—manganite thin films,” J. Appl. Phys., Condens. Matter 9, pp.8171-8174, 1997.
19. Clarenece Zener, “Interaction Between the d Shells in the Transition Metals,” Phys. Rev. Vol. 81, pp.440-444, 1951.
20. 范文亮，淺介GMR，工業材料，Vol. 87，pp. 94-99，1994。
21. 吳宗展，龐磁阻磁穿隧之研究，中山大學物理研究所，2002年6月。
22. T. R. McGuire and R. I. Potter, “Aging of an Fe-Ni-Al alloy in magnetic field,” IEEE Trans. Mag., Vol. 61, No. 12, pp.1333-1336, 1993.
23. T. P. McGuire and R. I. Potter, “Influence of static magnetic field on infection of Escherichia coli to HeLa cells,” IEEE Trans. Mag. MAG-11, Vol. 9, No. 4, pp. 242-246, 1975.
24. P. Grungerg, R. Schreiber, Y. Pang,V. Walz, M. B. Brodsky and H. Sower, “Separation of minerals by selective magnetic fluidization”, J. Appl. Phys., Vol. 61, No. 3, pp.3750-3756, 1987.
25. G. Binash, P. Gurngerg, F. Saurenbach and W. Zinn, “Magnetic analysis of an overlapped cantilever beam magnetic microactuator using finite elements,” Phys. Rev., Vol. 39, No. 4, pp.4828-4831, 1989.
26. J. J. Kerbs, P. Lubitz, A. Chaiken and G. A. Prinz, “Inductive sensor for slow varying magnetic field,” Phys. Rev. Lett. Vol. 63, No.1, pp. 1645-1646, 1989.
27. Jin, T. H. Tiefel, M. McCormak, R. A. Fastnacht, R. Ramesh, and L.H. Chen, “Thousandfold Change in Resistivity in Magnetoresistive La-Ca-Mn-O Films,” Science, Vol. 264, pp. 413-414, 1994.
28. R. M. Kuster, J. singleton, D. A. Keen, R. McGreevy and W. Hayes, “Magnetoresistance Measurements on the Magnetic Semiconductor Nd0.5Pb0.5MnO3,” Phys., Vol. 155, pp. 362-365,1989.
29. R. von Helmolt, J. Wecker, B. Holzapfel, L. Schultz and K. Samwer, “Giant Negative Magnetresistance in Perovskitelike La2/3Ba1/3MnOX Ferromagnetic Films,” Phys. Rev. Lett., Vol. 71, pp. 2331-2233, 1993.
30. L. H. Chen, T. H. Tiefel S. Jin, T. T. M. Palstra, R. Ramesh, and C. Kwon, “Colossal Magnetoresistance in La-Y-Ca-Mn-O Films,” IEEE trans. on Mag., Vol. 32, pp. 4692-4694, 1996.
31. J. F. Lawler and J.M.D. Coey, “Magnetoresistance in （La1-XCaX）MnO3 films,” Journal of Magnetism and Magnetic Materials, Vol. 140-144, pp. 2049— 2050, 1995.
32. B. Raveau, “Colossal magnetoresistance, Charge Ordering and Related Properties of Manganese Oxides,” J. Appl. Phys., Vol. 61, No. 3, pp. 3695 - 3702, 1987.
33. 劉如熹，具電洞導電與離子導電之錳系化合物合成及其特性研究，博士論文，台灣大學化學研究所， 2001。
34. P. Grunberg, R. Schreiber, Y. Pang, M. B. Brodsky and H. Sowers, “Layered Magnetic Structures: Evidence for Antiferromagnetic Coupling of Fe Layers across Cr Interlayers,” Phys. Rev. Lett. Vol. 57, pp.2442-2446, 1986.
35. A. Hellemans, “Composite polaron mechanism for colossal magnetoresista-
nce in perovskite manganites,” Science Vol. 273, pp. 880-883, 1996.
36. D. D. Tang, P. K. Wang, V. S. Speriosu, S. Le, K. K. Kung, “Spin-Valve RAM Cell”, IEEE Transactions Magnetics, Vol. 31, pp. 3206-3208, 1995.
37. J. Topfer, J. B. Goodenought, “Charge transport magnetic properties in perovskites of the system La-Mn-O,” Solid State Ionics, Vol. 101-103, pp.1215-1219, 1997.
38. N. F. Mott, “Evidence of local lattice distortions in La1—xSrxMnO3 provided by pulsed neutron diffraction,” Adv. Phys., Vol. 21, pp. 785-788, 1972.
39. R. M. Kusters, J. Singleton, D. A. Keen, R. Mc. Greevy and W. Hayes, “Long wavelength spin dynamics in La0.53Ca0.47MnO3,” Physica, B. 45, pp. 9819-9823, 1992.
40. 陳立翰，中華民國磁性技術學會會訊，第十九期，pp. 27-31，1999。
41. C. Zener, “Interaction Between the d Shells in the Transition Metals,” Phys. Rev. Vol. 81, pp. 440-445, 1951.
42. P. G. de Gennes, “Effect of double exchange in magnetic crystals,” Physica Review, Vol. 118, pp.141-145, 1960.
43. A.Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido, Y. Tokura, “Insulator-metal transition and gaint magnetoresistance in La1-xSrxMnO3,” Phys. Rev., B. 51, pp.14103-14108, 1995.
44. C. Zenner, “Interaction between the d-shell in the transition metal II Ferromagntic compounds of manganese with perovskite structure,” Phys. Rev. Vol. 82, pp.403-413, 1951.
45. A. J. Mills, P. B. Littlewood, B. I. Shraiman, “Double Exchange Alone Does Not Explain the Resistivity of La1-xSrxMnO3,” Phys. Rev. Lett. B. 74, pp. 5144-5149, 1995.
46. H. Sawada, Y. Morikawa, K. Terakura, N. Hamada, “Jahn-Teller distortion and magnetic structures in LaMnO3,” Phys. Rev. B. 56, pp. 12154-12158, 1997.
47. H. Sawada, Y. Morikawa, N. Hamaka, K. Terakura,“Jahn-Teller distortion and magnetic structures in LaMnO3,” J. M. M. M. Vol.177-181, pp. 879-886, 1998.
48. Y. Motome, M. Imada, “Phase diagram of manganese oxides,”J. Phys. Soc. Jap. B. 68, pp. 16-21, 1999.
49. D. J. Singh, W. E. Pickett, “Lattice effects in ferromagnetic manganite perovskites,” J. Appl. Phys. B. 83, pp. 7354-7359, 1998.
50. A. J. Mills, “Electron-lattice coupling in "colossal" magnetoresistance rare earth manganites,” J. Appl. Phys. B.81, pp. 5502-5507, 1997.
51. J. W. Liu, Z. Zeng, Q. Q. Zheng, H. Q. Lin, “Effective transfer integrals for the Jahn-Teller distortion in LaMnO3,” Phys. Rev. B. 60, pp. 12968-12972, 1999.
52. L. F. Schelp, A. Fert, F. Fettar, P. Holody, S. F. Lee, J. L. Maurice, F. Oetroff, and A. Vaures, “Spin-dependent tunneling with Coulomb blockade,” Phys. Rev. B. 56, pp. 5747-5750, 1997.
53. S. Takahashi and S. Maekawa, “Effect of Coulomb Blockade on Magnetoresistance in Ferromagnetic Tunnel Junctions,” Phys. Rev. Lett. B. 80, pp. 1758-1762, 1998.
54. J. Inoue , “Magnetic and Transport Properties of Mn Oxides Films,” I. Phys. D. Appl. Phys. B. 31, pp. 643-649, 1998.
55. T. Tokura, A. Urushibara, Y. Moritomo, A. Asamitsu, Y. Tomioka, T. Arima, and G. Kido, “Giant magnetotransport and magnetostructure phenomena in hole doped manganese oxides,” Mater. Sc. Engi., B 31, pp. 187-190, 1995.
56. V. Nossov, A. Pierre, J. Vassiliev, V. Ustinov, “Influence of annealing conditions on the magnetoresistance of (La-Y-Ca) manganites,” Solid State Communications, Vol. 101, No. 5, pp. 361-366, 1997.
57. S. Pignard, H. Vincent, J. P. Senateur, J. Pierre, and A. Abrutis, “Annealing effect on magnetic and electrical properties of epitaxial La0.8MnO3-δ thin films grown by chemical Vapor deposition,” J. Appl. Phys., Vol. 82, pp. 4445-4449, 1997.
58. T. Kaneta, K. Matsushita, N. Nakagawa, S. Naoe, “Annealing effect on magnetic characteristics on (La,Sr)MnO/sub3/sputtered films,” IEEE Transactions on Magnetics, Vol. 35, Issue 5, pp. 2850-2857 , 1999.
59. 陳國駒，鑭錳系氧化物膜之磁性、電性及磁阻效應研究，國立成功大學材料科學及工程研究所博士論文，2000。
60. M. Venkatesan, T. Ramesh, R. Radmilovic, V. Dahmen, U. Thomas, “In-plane grain boundary effects on the magnetotransport properties of La0.67Sr0.33MnO3-δ,” J. Appl. Phys. Lett.,Vol. 72, No. 9, pp. 1113-1119, 1998.
61. N. D. Mathur, G. Burnell, S. P. Issac, T. J. Jackson, B. S. Teo, J. L. MacManus-Driscoll, L. F. Gohen, J. E. Evetts and M. G. Blamire, “Large low-field magnetoresistance in La0.7Ga0.3MnO3 induced by artificial grain boundaries,” NATURE, Vol. 387, pp. 266-268, 1997.
62. 歐敏男，La1-xAxMnO3(A=Ca,Sr)薄膜增強磁阻效應之研究，中山大學物理研究所碩士論文，2000。
63. 莊達人，VLSI製造技術，高立圖書有限公司，1997。
64. 賴耿陽，製程之濺射技術，復漢出版社，1994。