跳到主要內容

簡易檢索 / 詳目顯示

回結果列表
研究生： 王進威
Chin-Wei Wang
論文名稱： 利用中子繞射探討多鐵材料之晶體結構及磁結構
Crystalline and magnetic structures of Multiferroic Compounds Studied by Neutron Diffraction
指導教授： 李文献
Wien-Hsien Li
口試委員:
學位類別： 博士
Doctor
系所名稱： 理學院 - 物理學系
Department of Physics
畢業學年度： 98
語文別： 英文
論文頁數： 71
中文關鍵詞： 多鐵材料 、中子繞射
外文關鍵詞： mutiferroic, neutron diffraction
相關次數： 點閱：17  下載：0 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 同時具有鐵磁及鐵電有序的材料稱之為多鐵材料，而其中具有磁性電性交互作用的材料又特稱為磁電材料，此類型的材料在元件設計的應用上具有相當的淺力，依照磁與電的偶合方式來區分主有有兩大類，分別是稀土元素錳氧化物(RMn2O5)以及鉍鐵氧。本論文研究在此兩類型中各取一作為研究對象，鈥鑭錳氧及鉛鉍鐵氧。
    本論文主要探討兩樣品的晶格結構以及磁性在摻雜之後所造成的變化。研究方法包含巨觀磁性量測、X光繞射、中子繞射和拉曼光譜等。
    在鈥鑭錳氧樣品中，我們發現摻雜濃度達20%時，可以在140K以下開始觀察到新的磁性反應，拉曼散射譜圖在同一溫區也觀察到新的散射峰。此外，低溫長程磁有序的行為也因未摻雜而改變。鉛鉍鐵氧方面發現低溫磁結構也因為鉛的摻雜而改變了，根據中子繞射的數據顯示，磁結構為簡單反鐵磁。

    The magnetic susceptibility, x-ray diffraction, neutron diffraction and Raman scattering measurements are employed to study the effects of La-substitution on the magnetic properties of multiferroic HoMn2O5. Both 9% and 18% La-doped compounds crystallize into the same orthorhombic Pbam symmetry as the parent compound. The magnetic responses to an ac driving magnetic field between 40 and 140 K are greatly enhanced by 18% La-doping. The neutron magnetic diffraction patterns reveal the development of short range magnetic correlations below 140 K. In addition, two Raman peaks and a series of new x-ray diffraction peaks suddenly develop below this temperature. Incommensurate long range antiferromagnetic order appears below 38 K. Magnetic frustration could be the main mechanism governing the present observations.
    Two Pb-doped BiFeO3 (5% and 10%) compounds were studied. The macroscopic magnetic measurement show the typical feature of the antiferromagnetic material. Weak ferromagnetic signals and the indication of spin reorientation at low temperatures were also observed in the two compounds. The magnetic structures for the two samples are basically simple antiferromagnetic arrangement but the magnetic moment direction is not yet determined. Further studies are still needed for complete understanding of the samples.

    Abstract in English………………………………………………..i Abstract in Chinese…………………………………………………ii Acknowledgment……………………………………………………..iii Table of Contents……………………………………………………………...v List of Figures………………………………………………………......vii List of Tables…………………………………………………………………..x Chapter 1 Introduction……………………………………………………….. 1 1-1 General Properties of RMn2O5…………………………1 1-2 Some Properties of HoMn2O5 and LaMn2O5…………..4 References……………………………………………………………..5 Chapter 2 Experimental………………………………………………………..7 2-1 Neutron Powder Diffraction Basis………………………...7 2-1-1 Rietveld Method……………………………………………………8 2-1-2. Diffraction Intensity from Nuclear Scattering………11 2-1-3. Magnetic Diffraction……………………………………………………….13 2-2 Instruments………………………………………………………15 2-2-1. X-ray diffraction…………………………….…………15 2-2-2. Neutron diffraction………………………………………17 2-2-3. Magnetic measurement (PPMS)……………………………19 2-2-4. Raman spectroscopy…………………………………………20 Reference………………………………………………………………21 Chapter 3 Characterization and Analysis…………………………………………….22 3-1 Synthesize Ho1-xLaxMn2O5 using the Sol-Gel Technique22 3-2 Structural Related Properties………………………….23 3-2-1 Crystalline Structure………………………………………….…………….23 3-2-2 Thermal Variations of Lattice Parameters…………………………………………………..28 3-2-3 Thermal Variations of Bond Valence and the global instability index………………………………………30 3-3 Macroscopic Magnetic Properties…………………………………………………….34 3-4 Results of Neutron Experiments…………………………………………………….41 3-4-1 Magnetic corrections………………………………………………………..41 3-4-2 Long ranger magnetic order…………………………………………………………………42 3-5 The Raman Spectroscopy………………………………………………………...45 3-6 Discussion and Conclusions………………………………………………………….49 Reference…………………………………………………………….51 Chapter 4 Effects of Pb-doping on the Multiferroic BiFeO3…………………………50 4-1 Introductions…………………………………………………………50 4-2 Fabrication of Bi1-xPbxFeO3…………………………………………………….53 4-3 Sample Characterization…………………………………………………..54 4-4 Macroscopic Magnetic Properties……………………………………………….56 4-5. Neutron Diffraction Results…………………………………………………….61 4-6 Discussions and Conclusions…………………………………………………….68 Reference…………………………………………………………….70

    ch1
    1. Schmid H, Ferroelectrics 162, 317 (1994).
    2. Fiebig M, Lottermoser Th, D Fröhlich, A V Goltsev and R V Pisarev, Nature (London) 419, 818 (2002).
    3. Hur N, Park S, Sharma P A, Guha S, and Cheong S-W, Phys. Rev. Lett. 93, 107207 (2004).
    4. Makoto T, Keita A, Hitoshi K, and Tooru A, Phys. Rev. B 72, 224425 (2005)
    5. Alonso J A, Casais M T, Martínez-Lope M J, Martínez J L and Fernández-Díazz M T, J. Phys.: Condens. Matter 9, 8515–8526 (1997).
    6. Higshiyama D, and Miyasaka S, Phys Rev. B 72 064421 (2005)
    7. Blake G R, Chapon L C, Radaelli P G, Park S, Hur N, Cheong S-W, and Rodríguez-Carvajal J, Phys. Rev. B 71, 214402 (2005).
    8. Vecchini C, Chapon L C, Brown P J, Chatterji T, Park S, Cheong S-W and Radaelli P G, Phys. Rev. B 77 134434 (2008).
    9. Muñoz A, Alonso J A, Casais M T, Martínez-Lope M J, Martínez J L and Fernández-Díaz M T, Phys. Rev. B 65 144423 (2002).
    10. Kobayashi S, Osawa T, Kimura H, Noda Y, Kagomiya I and Kohn K, J. Phys. Soc. Jpn. 73 pp. 1031-1035 (2004).
    11. Fukunaga M, Nishihata K, Kimura H, Noda Y, and Kohn K, J. Phys. Soc. Jpn. 76 074710 (2007).
    12. Kobayashi S, Kimura H, Noda Y and Kohn K, J. Phys.Soc. Japan 74 468 (2005).
    13. dela Cruz C R, Yen F, Lorenz B, Gospodinov M M, Chu C W, Ratcliff W, Lynn J W, Park S, and Cheong S –W, Phys. Rev. B 73, 100406(R) (2006).
    14. Chapon L C, Blake G R, Gutmann M J, Park S, Hur N, Radaelli P G, and Cheong S-W Phys. Rev. Lett. 93, 177402 (2004).
    15. Kobayashi S, Osawa T, Kimura H, Noda Y, Kagomiya I and Kohn K, J. Phys. Soc. Jpn. 73 pp. 1593-1596 (2004).
    16. Ma C, Yan J-Q, Dennis K W, Llobet A, McCallum R W and Tan X, J. Phys.: Condens. Matter 21 346002 (2009)
    17. Chen Y, Yuan H, Tian G, Zhang G, Feng S, J. Sol. Stat. Chem. 180 1340 (2007).
    18. Golovenchits E and Sanina V, J. Phys.: Condens. Matter 16 4325–4334 (2007).
    19. Fukunaga M, Nishihata K, Kimura H, Noda Y and Kohn K, J. Phys. Soc. Japan 77 094711 (2008).
    20. Kimura H, Noda Y, and Kohn K., J.Magn.Magn.Mater. 321 854-857 (2009).
    21. Radaelli P G and Chapon L C, J. Phys.: Condens. Matter 20 434213 (2008)
    22. Radulova I, Lovchinova V, Daszkiewicz M, Journal of Magnetism and Magnetic Materials 320 43–46 (2008).
    23. Muñoz A, Alonso J A, Casais M, Martínez-Lope M J, Martínez J L and Fernández-Díaz M T, Eur. J. Inorg. Chem. 685–691 (2005).
    ch2
    1. Rietveld H M, Acta Crystallogr. 22, 151-2. (1967)
    2. Rietveld H M, J. Appl. Crystallography. 2, 65 (1969)
    3. Young R A edited, The Rietveld Method (Oxford University Press, New York, (1993). (ISBN 0198555776)
    4. Taylor J C, Rietveld made easy: a practical guide to the understanding of the method and successful phase quantifications, Canberra: Sietronics Pty Ltd (2001). (ISBN 0975079808)
    5. http://www.ccp14.ac.uk/solution/rietveld_software/index.html
    6. Toby B H, J. Appl. Cryst. 34, 210-213, (2001).
    7. Larson A C and von Dreele R B, GSAS Manual, p167
    8. Bacon G E, Neutron Diffraction (Oxford University Press, Oxford, 1975)
    9. Lovessey S W, Theory of Neutron Scattering from Condensed Matter, Vol. 1&2 (Oxford University Press, New York, 1984)
    10. Larson A C and von Dreele R B, GSAS Manual, p134.
    11. http://www.ncnr.nist.gov/instruments/bt1/neutron.html.
    12. Wilkinson C, J. Appl. Cryst. 24, 365-368 (1991)
    ch 3
    1. Radaelli P G and Chapon L C, J. Phys.: Condens. Matter 20, 434213(2008)
    2. Alonso J A, Casais M T, Martinez-Lope M J and Rasines I, J. Solid State Chem. 129, 105 (1997).
    3. Yu C C, Huang S Y, Yeh C J, Lee C W, Wu C B, and Chou H, J. App. Phys. 103, 07E310. (2008)
    4. Larson A C and von Dreele R B, GSAS Manual, p160.
    5. O’Keeffe M and Hyde B G, Acta Crystallogr., Sect. B. Crystallogr. Cryst. Chem. 33, 3802 (1977).
    6. Brese N E and O’Keeffe M, Acta Cryst. B47, 192-197 (1991).
    7. Alonso J A, Casais M T, Martínez-Lope M J, Martínez J L and Fernández-Díazz M T, J. Phys.: Condens. Matter 9, 8515–8526 (1997).
    8. Brown I D, Z. Kristallogr. 199 255 (1992).
    9. dela Cruz C R, Yen F, Lorenz B, Gospodinov M M, Chu C W, Ratcliff W, Lynn J W, Park S, and Cheong S-W, Phys. Rev. B 73, 100406(R) (2006).
    10. Blake G R, Chapon L C, Radaelli P G, Park S, Hur N, Cheong S-W, and Rodríguez-Carvajal J, Phys. Rev. B 71, 214402 (2005).
    11. Mihailova B, Gospodinov M M, Güttler B, Yen F, Litvinchuk A P, and Iliev M N, Phys. Rev. B 71, 172301 (2005).
    12. Litvinchuk A P, Journal of Magnetism and Magnetic Materials 321 2373-2377 (2009).
    ch 4
    1. Michel C, Moreau J -M, Achenbach G D, Gerson R and James W J, Solid State Commun. 7 701 (1969).
    2. Kubel F and Schmid H, Acta Crystallogr., Sect. B:Struct. Sci. 46 698 (1990).
    3. Blaauw C and van der Woude F, J. Phys. C: Solid St. Phys. 6 1422-31 (1973).
    4. Wollan E O and Koehler W C, Phys. Rev. 100 545-563 (1955).
    5. Zhang S- T, Zhang Y, Lu M- H, Du C- L, Liu Z-G, Zhu Y- Y and Ming N- B, Appl. Phys. Lett. 88 162901 (2006).
    6. Yuan G- L and Or S- W, Appl. Phys. Lett. 89 052905 (2006).
    7. Khomchenko V A, Kiselev D A, Vieira J M, Kholkin A L, Sá M A and Pogorelov Y G, Appl. Phys. Lett. 90 242901 (2007).
    8. Mazumder R and Sen A, Journal of Alloys and Compounds 475 577-580 (2009).
    9. Chaigneau J, Haumont R, and Kiat J M, Phys. Rev. B 80 184107 (2009).
    10. Khomchenko V A, Kiselev D A, Vieira J M, Rubinger R M, Sobolev N A, Kopcewicz M, Shvartsman V V, Borisov R , Kleemann W, and Kholkin A L, J. Phys.: Condens. Matter 20 155207 (2008).
    11. Yu B. Li M, Liu J, Guo D, Pei L and Zhao X, J. Phys. D: Appl. Phys. 41 065003 (2008).
    12. Jun Y- K and Hong S-H, Solid State Commun. 144 329-333 (2007).
    13. Jacobson A J and Fender B E F, J. Phys. C: Solid State. Phys. 8 844 (1975).
    14. Lebeugle D, Colson D, Forget A Viret M, Bonville P, Marucco J F, and Fusil S, Phys. Rev. B 76 024116 (2007).
    15. Lu J, Gunther A, Schrettle F, Mayr F, Krohns S, Lunkenheimer P, Pimenov A, Travkin V D, Mukhin A A and Loidl A, arXiv:0910.0385v1 [cond-mat.mtrl-sci] (2009).
    16. Ederer C and Spaldin N A, Phys Rev. B 71, 060401(R) (2005)
    17. Lu J, Gunther A, Schrettle F, Mayr F, Krohns S, Lunkenheimer P, Pimenov A, Travkin V D, Mukhin A A and Loidl A, arXiv:0910.0385v1 [cond-mat.mtrl-sci] (2009).
    18. https://www.ill.eu/sites/ccsl/ffacts/ffachtml.html

    QR CODE
    :::