臺灣博碩士論文加值系統

多鐵性材料是個磁電耦合材料，可以利用改變電場來控制材料中的電偶極矩，而利用電偶極矩去影響鄰近層的磁矩方向，相反的，亦可利用磁矩來影響電偶極矩。至今為止，BiFeO3鐵酸鉍是最重要同時鐵電性轉變溫度(TC≒1103K)與反鐵磁性轉變溫度(TN≒643K) 皆在室溫的以上的多鐵性材料。然因BiFeO3的準正方結構，具有八個近乎簡併的電偶極矩，導致以往延[100]方向成長之薄膜面對極為複雜的偏極化取向。再加上電疇邊界漏電的缺陷而無法順利應用。本研究擬採用延[111]方向成長薄膜來簡化偏極化取向，以及使用摻鉛Pb的BiFeO3來克服電疇邊界漏電的問題。實驗上則利用脈衝雷射濺鍍法，在原子級平整SrTiO3(111)基板上成長出高品質SrRuO3與摻鉛Pb的BiFeO3雙層薄膜，借由壓電反應顯微鏡(piezoresponse microscope) 來研究上述的問題。實驗結果證實我們的想法完全正確。

Multiferroics is a material involving multiple couplings between electricity, magnetism and strain and, therefore, has great potential for applications, such as memory devices. Especially for magnetoelectric multiferroics which possesses inherent coupling between magnetic and ferroelectric order parameters that could be used as an indirect mechanism to switch magnetic moment of adjacent magnetic layer by changing the polarity of the electric field and vice-versa. Up to date, BiFeO3 is the best candidate for it exhibits ferroelectric (TC≒1103K) and antiferromagnetic ordering temperature (TN≒643K) above room temperature. However, due to the pseudocubic structure of BiFeO3 crystal, eight degenerate electric polarization along diagonal directions that are very difficult to control, and the electric leakage at domain walls challenge the application technique. In our research, we trys to overcome these obstacles by growing BiFeO3 films along [111] direction and use Pb-doped BiFeO3 to stop the electric leakage. The Pb-doped BiFeO3 film were grwon on atomically flat SrTiO3 (111) substrates by a pulse laser ablation technique. The electric polarization of Pb-doped BFO was observed by a piezoresponse microcope. In this project, we success in overcome all these difficulties and accomplish the goal to switch the electric polarization of the system along out-of-plane direction.

論文審定書 i
誌 謝 ii
摘 要 iii
Abstract iv
目 錄 v
圖 次 vii
第一章 前言 1
第二章 基本理論介紹 2
2-1 磁性物質的簡介 2
2-1-1 順磁性(Paramagnetic) 3
2-1-2 反磁性(Diamagnetic) 4
2-1-3 鐵磁性(Ferromagnetic) 5
2-1-4 亞鐵磁性(Ferrimagnetic) 7
2-1-5 反鐵磁性(Anti-ferromagnetic) 8
2-2 介電極化特性 9
2-3 SrRuO3材料特性 11
2-4 BiFeO3鐵酸鉍材料特性 14
第三章 實驗方法、量測系統 22
3-1 SrTiO3(111)基板清洗 22
3-2 Bi0.9Pb0.1FeO3/SrRuO3薄膜成長 24
3-3 脈衝式雷射鍍膜系統(Pulsed Laser Deposition) 26
3-4 光學微影製程 28
3-5 X光繞射儀(X-Ray Diffraction system) 30
3-6 穿透式電子顯微鏡(Transmission Electron Microscope) 31
3-7 原子力顯微鏡(Atomic Force Microscopy, AFM) 32
3-8 電性量測 33
第四章 實驗結果與討論 34
4-1 SrTiO3(111)基板酸蝕處理比較 34
4-2 SrRuO3薄膜表面形貌分析(AFM) 38
4-3 Bi0.9Pb0.1FeO3薄膜表面形貌分析(AFM) 43
4-4 漏電流量測 45
4-5 壓電力顯微術量測 48
4-6 穿透式電子顯微鏡量測 56
第五章 結論 60
參考資料 61

[1]Feng, J., Zhu, X., & Guo, J. (2013). Reconstructions on srtio 3 (111) surface tuned by ti/sr deposition. Surface Science,614(4), 38-45.
[2]Chang, S. H., Danilovic, N., Chang, K. C., Subbaraman, R., Paulikas, A. P., & Fong, D. D., et al. (2014). Functional links between stability and reactivity of strontium ruthenate single crystals during oxygen evolution. Nature Communications, 5, 4191.
[3]Kingery, W. D. (1960). Introduction to ceramics. Journal of the Electrochemical Society, 124(3), 152C.
[4]Yeh, S. R. (2010). Research structure and strain effect of PBFO/SRO/STO thin films.
[5]Peng, C. C. (2009). Thickness dependence multiferroics property ofbi0.9pb0.1feo3 thin film. Physics.
[6]Hung, B., & Chanyu. (2007). The surface modification of srtio3(100) and physical properties research on cmr thin films. Physics.
[7]Chang, B., & Chinchien. (2007). Dielectric properties research on bi1-xpbxfeo3. Physics.
[8]Zueng-en Bao (2007). The ferroelectric property of la and pb codoped multiferroic bifeo3. Physics.
[9]Cheung, J. T. (1994). The growth of heterostructures by pulsed laser deposition. Laser & Ion Beam Modification of Materials, 25-30.
[10]Liu, K. C. (2012). Study of Film Growth Ferroelectricity on Bi0. 9Pb0. 1FeO3/SrRuO3/SrTiO3.
[11]胡裕民. (2000). 鐵磁/反鐵磁金屬薄膜之間的交換磁異向性. 物理雙月刊, 22.
[12]Heron, J. T., Schlom, D. G., & Ramesh, R. (2014). Electric field control of magnetism using bifeo3-based heterostructures. Cheminform, 1(2), 297-302.
[13]Yen, C. W. (2014). Anomalous Enhancement on Magnetic Ordering by Divalent Ions Doping of (Bi0. 9M0. 1) FeO3 (M= Pb, Ca).
[14]Lebeugle, D., Colson, D., Forget, A., & Viret, M. (2007). Very large spontaneous electric polarization in bifeo3 single crystals at room temperature and its evolution under cycling fields. Applied Physics Letters, 91(2), 022907-022907-3.
[15]Paramagnetism. Enwikipediaorg. 2017. Available at: https://en.wikipedia.org/wiki/Paramagnetism. Accessed July 27, 2017.
[16]Classes of Magnetic Materials. Googl. 2017. Available at: https://goo.gl/hnAwjI. Accessed July 27, 2017.
[17]2017. Available at: http://ferro.unige.ch/theses/jill_guyonnet_master.pdf. Accessed July 27, 2017
[18]Piezoresponse Force Microscopy. Asylumresearchcom. 2017. Available at: https://www.asylumresearch.com/Applications/PFMAppNote/PFMAppNote.shtml. Accessed July 27, 2017
[19]Wang, S., Kunfang, L. I., Fang, T., Wang, S., Zhou, X., & Yu, S. U., et al. (2014). Research of room-temperature ferroelectric properties for the pb doped bifeo_3. Materials Review.
[20]Kats, Y., & אבגני כץ. (2004). Extraordinary Hall effect in SrRuO3. Bar-Ilan University, Department of Physics..
[21]Bohra, M., Wu, C. P., Yeh, H. J., & Chou, H. (2012). Strain relaxation in bi0.9pb0.1feo3/srruo3/srtio3 heterostructures. Journal of Applied Physics, 111(7), 478-4.
[22]康立敏. (2014). 多铁性铁酸铋薄膜的磁控溅射制备及其性能研究. (Doctoral dissertation, 山东大学).
[23]Huang, T. C. (2015). Study of Magnetic and Transport Properties of La0. 7Sr0. 3MnO3 (111) Thin Films.
[24]Yao, X. F., Zhang, J. X., Physics, D. O., & University, B. N. (2014). Decade of advances in the most desired magnetoelectric multiferroic material——bifeo_3. Physics.
[25]SergeiKalinin, & AlexeiGruverman. (2007). Scanning Probe Microscopy. Springer New York.
[26]SergeiKalinin，AlexeiGruverman - Springer New York(2007), Scanning Probe Microscopy
[27]Weber, D., Vőfély, R., Chen, Y., Mourzina, Y., & Poppe, U. (2013). Variable resistor made by repeated steps of epitaxial deposition and lithographic structuring of oxide layers by using wet chemical etchants. Thin Solid Films, 533(5), 43-47.
[28]Kittel, C. (2005). Introduction to solid state physics. Wiley.
[29][image] Available at: http://www.fhi-berlin.mpg.de/~hermann/Balsac/BalsacPictures/SrTiO3111.gif
[30]Chang, J., Park, Y. S., & Kim, S. K. (2008). Atomically flat single-terminated Sr Ti O 3 (111) surface. Applied Physics Letters, 92(15), 152910.
[31]Shima, H., Naganuma, H., & Okamura, S. (2013). Optical properties of multiferroic BiFeO3 films. In Materials Science-Advanced Topics. InTech.
[32][image] Available at: http://iramis.cea.fr/spec/Phocea/Vie_des_labos/Ast/ast.php?t=fait_marquant&id_ast=1010
[33]Heron, J. T., Schlom, D. G., & Ramesh, R. (2014). Electric field control of magnetism using BiFeO3-based heterostructures. Applied Physics Reviews, 1(2), 021303.
[34]Bibes, M., & Barthélémy, A. (2008). Multiferroics: Towards a magnetoelectric memory. Nature materials, 7(6), 425-426.