本研究利用射頻磁控濺鍍系統製備複鐵式薄膜鐵酸鉍BiFeO3。實驗首先先在室溫下濺鍍成長BFO薄膜，然後再藉由高溫燒結的程序促使BiFeO3成相。在此過程中，吾人透過改變靶材成分、燒結溫度、持溫時間以及氧分壓的條件製備出各種BFO薄膜，並研究各試片樣品的性質，其中包含純度(雜質相)、顯微結構、表面型態以及漏電流等各方面性質。

由實驗結果發現，(1) BiFeO3相結構較易由富Bi成分之靶材濺鍍而得，(2)BFO在某些氧分壓範圍下較易成長(3)在單晶基板SrTiO3上可成長出高純度磊晶BFO薄膜。薄膜的鐵電量測皆顯示出所製備薄膜具有較大的漏電流存在，電滯迴線也由於如此而無法達到飽和的狀態，此外，實驗還發現漏電流有隨著退火溫度升高而上升的趨勢。

In this study, BiFeO3 films have been deposited by RF magnetron sputtering. The films were first sputtered at room temperature and then the BiFeO3 phase was formed after post-growth sintering at high temperature. A range of targets of varying compositions were used for the deposition of the suitable “precursor” films. The phase purity and microstructures of the sintered films were studied for different sintering temperatures and times, as well as different oxygen partial pressures. The leakage currents for the films prepared under different conditions were also examined.

We found that (1) BiFeO3 phase were easier to form in the films sputtered from the targets containing small excess of Bi, (2) the BFO structure only grew under certain oxygen partial pressures, (3) high-purity expitaxial BiFeO3 films could be grow on (001) SrTiO3 single crystal substrates under the optimum condition. The ferroelectric measurements showed that the films had large leakage currents and as a consequence, the polarization-electric field (P-E) hysteresis loops were unable to reach a saturated state. The leakage current had a tendency to increase as the annealing temperature.

1.B. Prince ,”Emerging Memories-Technologies and Trend”, Kluwer Academic Publishers ,4,2002
2.R. Ramesh , “Thin Film Ferroelectric Materials and Devices” , Kluwer Academic , London , Chap1-3,1997
3.J. F. Scott , and C. A. Araujo ,“Ferroelectric Memory ”,Scince,246,1400,1989
4.M. Fiebig, T. Lotter, D. Frohlich, A. V. Goltse, and R. V. Pisarev , ”Observation of Coupled Magnetic and Electric Domains”,Nature(London)419,818-820,2002.
5.J. Wang, J. B. Neaton, H. Zheng, V. Nagarajan, S.B. Ogale,B.Liu, D. Viehland, V. Vaithyanathan, D. G. Schlom, U. V. Waghmare,N. A. Spaldin, K.M. Rade, M . Wuttig, and R. Ramesh,”Epitaxial BiFeO3 Multiferroic Thin Film Heterostructures”, Sience, 299 , 1719-1722 , 2003.
6.W. Eerenstein, F. D. Morrison, J. Dho, M. G. Blamire, J. F.Scott, and D. D. Mathur,”Epitaxial BiFeO3 Multiferroic Thin Film Heterostructures”, Sience, 307, 1203 , 2005.
7.A. J. Moulson, J. M. Herbert, ”Electroceramics ”,Chapman and Hall,1990
8.T. Kimura, T. goto , H. Shintani, K. ishizaka, T. Arima, and Y. Tokura,”Magnetic Control of Ferroelectric Polarization”, Nature(London)426,55-58,2003.
9.V. A. Murashav, D. N. Rakov, V. M.Ionov, I. S. Dubenko, Y . U. Titov,Ferroelectrics,162,11,1994
10.Y. F. Popov, A. M. Kadomtseva, G. P. Vorobev, A. K. Zvezdin ,”The Nature of The Dielectric and Magnetic Properties of BifFeoO3 ”,Ferroelectrics, 162, 135, 1994
11.K. U. H. Tabata and T. Kawai, “Coexistence of ferroelectricity and ferromagnetism in BiFeO3-BaTiO3 thin film at room temperature”, Appl. Phys. Lett. 75, 555 (1999).
12.X, Qi, J. Dho, R. Tomov, M. G. Blamire, J. L. MacManus-Driscoll, “Greatly reduced leakage current andconduction mechanism in aliovalent-ion-doped BiFeO3”, Appl. Phys. Lett. 86, 062903 (2005).
13.H. Uchida, R. Ueno, H. Nakaki, H. Funakubo and S. Koda,”Ion Modification for Improvement of Insulating and Ferroelectric Properties of BiFeoO3 Thin Films Fabricated by Chemical Solution Deposition “,J. J. Appl. Phys., 44(18), Ll561-l563, 2005
14.G. Burns, Solid state physics, (Academic Press, New York,1985).
15.H. S. Nalwa, “Ferroelectric and dielectric thin films”, (Academic press, New York, 2002).
16.M. M. Kumar and V. R. Palkar ,”Ferroelectricity in a pure BiFeO3 ceramic”, Appl. Phys. Lett. 76, 2764 (2000).
17.C. Ederer and N. A. Spaldin, “Weak ferromagnetism and magnetoelectric coupling in bismuth ferrite”, Phys. Rev B 71, 060401 (2005).
18.C. Michel, “The atomic structure of BiFeO3”, Solid State Communication 7, 701 (1969)
19.呂正傑,詹世雄,鐵電記憶體簡介,奈米通訊,第五卷第四期(1998).
20.鄭佩慈,真空技術組,儀器科學中心簡訊,68期,中華民國九十四年4月30日出版
21.R. J. H. Voorhoeve, Advanced Mate. Catal. ; Academic Press: New York, (1977)
22.G . shirane , F. Jona, and R. Pepinsky, Proc. I.R.E., 42, 1738(1955)
23.Y. Xu ,“Ferroelectric Materials and their Applications”, North Holland , Amsterdam , 1991.
24.Kingery ,Bowen ,uhlmann ,陶瓷材料概論 ,皢園出版社 ,初版 ,1988年4月
25.曲遠方主編 ,新材料與技術應用叢書 ,功能陶瓷材料 ,初版 03,2006
26.J. Wang.” Deposition and Characterization of Multiferroic BiFeO3 Thin Films”. PhD dissertation, University of Maryland, Department of Materials Science and Engineering, 2005
27.B. H. Park, B. S. Kang, S. D. Bu, T. W Noh, J. Lee and W. Jo,
“Lanthanum- substituted bismuth tianate for use in non-volatile memories”, Nature 401, 682 (1999)
28.M. E. Lines and A. M. Glass,” Principles and applications of ferroelectrics and related materials”, (Oxford University ,New York,2001).
29.M. Barsoum, Fundamentals of ceramics, (McGraw Hill, New York , 1994).
30.林麗娟，X光繞射原理及其應用，工業材料86期，83年2月.
31.W. D. Kingery, H. KBrown, and D. R. Uhlmann,” Introduction to ceramics”, 2nd Ed., John Wiley and Sons, New York,Chper.2,1976
32.M. E. Lines and A. M. Glass , ”Principles and application of ferroelectrics and related materials ”,Oxford University Press, New York,Chap.2-5,2001.
33.張志嘉,摻雜鑭、矽之鐵酸鉍多鐵性薄膜製備與特性之研究,國立成功大學材料科學及工程學系碩士班,碩士論文,2006
34.S. M. Sze, Physics of Semiconductor Devices, New York: Wiley, 1981.
35.Y. S. Yang, S. J. Lee, S. H. Kim, B. G. Chae, and M. S. Jang,
“Schottky barrier effects in the electronic conduction of sol–gel derived lead zirconate titanate thin film capacitors,”J. J. Appl. Phys.84 [9] 5005-5011 (1998).
36.Stolichnovb and A. Tagantsev,“Space-charge influenced - injection model for conduction in Pb(ZrxTi1-x)O3 thin films,”J. J. Appl. Phys. 84 [6] 3216-3225 (1998)
37.C. Kittel, “Introduction to solid state physics”, 7th ed. (John Wiley &Sons, New York, 1996).
38.J. A. C. Bland and B. Heinrich,”Ultrathin Magnetic Structure I”,Springer-verlag, Chap. 3,1994
39.K. Y. Yun, M. Noda and M. Okuyama,” Prominent ferroelectricity of BiFeO3 thin films prepared by pulsed-laer deposition”, Appl. Phys. Lett. 83, 3981 (2003).
40.F. Kubel and H. Schmid,” Structure of a ferroelectric and ferroelastic monodomain crystal of the pervskite BiFeO3”, Acta Cryst. B46, 698 (1990).
41.J. M. Moreau and C. Michel,“Ferroelectric BiFeO3 X-ray and neutron diffraction study”, J. Phys. Chem. Solid 32,1315(1971)
42.B. D. Cullity and S. R. Stock, Element of X-Ray diffraction, 3rd ed.(Prentice Hall, London 2001).
43.O. Muller and R. Roy,”The Major Ternary Structrual Families”, Springer, New Work,1974.
44.N. N. Krainik ,Sov. Phys. 8, 654, 1966
45.劉純宇, 碩士論文, BiFeO3 鐵電薄膜之製備與特性研究,成功大學材料科學與工程學系, 2005
46.吳奇錕, 鐵酸鉍與鈷鐵仰氧體之複合材料電性與磁性研究,清華大學材料科學與工程學系, 2007
47.M. I. Morozov, N. A. Lomanova, and V. V. Gusarov.” Specific features of BiFeO3 formation in a mixture of bismuth(III) and iron(III) oxides”. Russian Journal of General Chemistry, 73(11):1676-1680, 2003. Translated from Zhurnal Obshchei Khimi
48.B. Ruette, S. Zvyagin, A. P. Pyatakov, A. Bush, J. F. Li, V. I. Belotelov, A. K. Zvezdin, and D. Viehland. “Magnetic-field induced phase transition in BiFeO3 observed by high-field electron spin resonance”: cycloidal to homogenous spin order. Physical Review B, 69:064114-1-064114-7, 2004.
49.Gippius, D. F. Khozeev , E. N. Morozova ,and V. Zalessky, Phys . Stat . Sol.196(1),221,2003.
50.J. R. Teague, R. Gerson, and W. J. James,”Dielectric hysteresis in single crystal”,Solid State Comm. 12,1073,1970.
51.Y. P. Wang, L. Zhou ,M. F. Zhang, X. Y. Chen, J. M. Liu, and Z. G. Liu,”Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering”,Appl. Phys. Lett,84,1731-1733,2004.
52.V. R. Palkar , K. G. Kumara, S. K. Malik ,”Observation of room-temperature magnetoelectric coupling in pulsed – laser – deposited Bi0.6Tb0.3La0.1FeO3 thin films”,J. Phys. 58, 1003,2002.
53.K. Y. Yun, M. Noda, and M. Okuyama ,H. Saeki,H. Tabata. And K. Saito , ”Structural and multiferroic properties of BiFeO3 thin films at room temperature”, J. J. Appl. Phys.96,3399-3403,2004.
54.Y. E. Roginskaya , Y. Y. Tomashpol’skii, Y. N. Venevtsev, V. M. Petrov , and G. S. Zhdanov , “The Nature of the Dielectric and Magnetic Properties of BiFeO3,” Soviet Phys. JETP., 44, 1418,1966.
55.H. S. Gu ,J. M. Xue, Gao ,J. Wang ,”Doping effect of BiFeO3 in layered pervoskite SrBi2Nb2O9”,Materials Chemistry and Physics,75,105,2002.
56.R. T. Smith, G. D. Achenbach, R. Gerson, and W. J. James,
“Dielectric Properties of Solid Solution of BiFeO3 with Pb(Ti, Zr)O3 at High Temperature and High Frequency,”J. J. Appl. Phys., 39, 70,(1968)
57.H. J. Nam and D. K. Choi,” Formation of hillocks in Pt/Ti electrodes and effects and their effects on short phenomena of PZT films deposited by reactive sputtering”, Thin solid films 371,564 (2000).
58.Chia-ching Lee , Jenn-Ming Wu ,“Effect of film thickness on interface and electric propertice of BiFeO3 thin films”Applied surface science 253 (2007) 7069-7073
59.富士通與東京工業大學聯手開發FeRAM的新型材料,電子工程專輯,2006年08月10日
60.溫志遠,不同鉍含量與掺雜釔對鐵酸鉍氧化物薄膜的影響,清華大學材料科學與工程學系,碩士論文,2006
61.David R. Gaskell ,“Introduction to the thermodynamics of materials”, 4th ed ,Taylor & Francis, London,(359),2003