English  |  正體中文  |  简体中文  |  Post-Print筆數 : 20 |  Items with full text/Total items : 90029/119959 (75%)
Visitors : 24039658      Online Users : 180
RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    Please use this identifier to cite or link to this item: http://nccur.lib.nccu.edu.tw/handle/140.119/55038


    Title: 利用第一原理計算研究多鐵氧化物Cu3Mo2O9的磁性,電子態及鐵電性質
    Ab Initio Studies of The Magnetic, Electronic and Ferroelectric Properties of Multiferroic Oxide Cu3Mo2O9
    Authors: 蕭逸修
    Hsiao, Yi Hsiu
    Contributors: 郭光宇
    Guo, Guang Yu
    蕭逸修
    Hsiao, Yi Hsiu
    Keywords: 第一原理
    多鐵氧化物
    鐵電性
    幾何不穩定性
    Ab Initio
    multiferroic oxide
    ferroelectricity
    geometric frustration
    Date: 2012
    Issue Date: 2012-10-30 15:22:21 (UTC+8)
    Abstract: 在此論文中,我們利用第一原理計算研究多鐵材料Cu3Mo2O9的磁性、電子態及多鐵性質。我們發現在此系統中,電子與電子間的庫倫排斥力必須被考慮,以致於導帶與價帶間能隙能夠被良好地描述。由於晶體結構所導致的幾何不穩定性,系統的磁結構尚未在實驗測量中被確定。在我們的理論計算當中得到的磁結構與Vilminot等研究人員根據實驗結果猜測出的非線性反鐵磁結構類似。交換作用與自旋軌道耦合間的爭競決定了電子自旋方向的傾斜。計算所得到的交換作用係數與實驗結果吻合良好。利用Berry’s phase計算,我們得到了系統自發電極化的理論值,其強度與實驗量測值在同一個數量級。然而,在我們計算中得到的電極化方向(平行於b軸)與實驗(平行於c軸)不符。此外,我們發現一磁結構之理論電極化方向與實驗相符,然而其磁結構之對稱性與實驗不符。目前,尚未有第一原理計算研究此氧化物,我們希望此論文能夠對同樣有興趣研究此材料的研究人員有所幫助。
    In this thesis, we used the ab initio method to study a multiferroic oxide Cu3Mo2O9. The correlations of electrons must be considered in this system so that a reasonable energy gap can be obtained. Due to the geometric frustration of magnetic structure caused by crystal structure, the ground state spin configuration in this system still has not been determined experimentally. We found some spin configurations similar to the non-collinear anti-ferromagnetic spins configuration suggested by Vilminot et al.. Competition between exchange interactions and spin-orbit coupling effect determines the canting of spins on Cu atoms. The calculated exchange parameters agree with the experimental results well. By using Berry phase calculations, we obtained the theoretical value of spontaneous electric polarization. The strength of polarization in our results is in the same order of results of experiments. However, the direction of electric polarization we found (along b-axis) is different from the experimental measurements (along c-axis). We have found a spin configuration that the theoretical electric polarization of the state agrees with the experimental results. However, the symmetry of the spin configuration does not satisfy the conditions suggested by results of the neutron diffraction experiment. And, spins on neighboring Cu2 and Cu3 do not form a singlet dimer. Since there still is no ab initio calculation studying this oxide, we hope that our studies can help those who are also interested in this material.
    Reference: [1] P. Hohenberg andW. Kohn, ”Inhomogeneous Electron Gas”, Phys. Rev. 136, B864 (1964).
    [2] W. Kohn and L. J. Sham, ”Self-Consistent Equations Including Exchange and Correlation
    Effects”, Phys. Rev. 140, A1133 (1965).
    [3] M. Born and J. R. Oppenheimer, ”On The Quantum Theory of Molecules”, Ann. Physik
    84, 457 (1927).
    [4] L. H. Thomas, ”The Calculation of Atomic Fields”, Proc. Camb. Phil. Soc. 23, 542 (1927).
    [5] J. P. Perdew and A. Zunger, ”Self-interaction correction to density-functional approximations
    for many-electron systems”, Phys. Rev. B 23, 5048 (1981).
    [6] J. P. Perdew, J. A. Chevary, S. H. Vosko, K. A. Jackson, M. R. Pederson, D. J. Singh, and
    C. Fiolhais, ”Atoms, Molecules, Solids, and Surfaces: Applications of The Generalized
    Gradient Approximation for Exchange and Correlation”, Phys. Rev. B 46, 6671 (1992);
    48, 4978(E)(1993).
    [7] J. P. Perdew, K. Burke, and M. Ernzerhof, ”Generalized Gradient Approximation Made
    Simple”, Phys. Rev. Lett. 77, 3865 (1996).
    [8] J. H. de Boer and E. J. W. Verwey, ”Semi-Conductors with Partially and with Completely
    Filled 3d-Lattice Bands”, Proc. Phys. Soc. 49, 59 (1937).
    [9] J. Hubbard, ”Electron Correlations in Narrow Energy Bands.”, Proc. Roy. Soc. A 276, 238
    (1963).
    [10] J. Hubbard, ”Electron Correlations in Narrow Energy Bands. III. An Improved Solution”,
    Proc. Roy. Soc. A 281, 41 (1964).
    [11] A. Svane and O. Gunnarsson, ”Transition-Metal Oxides in The Self-Interaction-Corrected
    Density-Functional Formalism”, Phys. Rev. Lett. 65, 1148 (1990).
    [12] S. Massidda, M. Posternak and A. Baldereschi, ”Hartree-Fock LAPW Approach to The
    Electronic Properties of Periodic Systems”, Phys. Rev. B 48, 5058 (1993).
    [13] L. Hedin, ”New Method for Calculating The One-Particle Green’s Function with Application
    to the Electron-Gas Problem”, Phys. Rev. 139, A796 (1965).
    [14] A. I. Liechtenstein, V. I. Anisimov and J. Zaanen, ”Density-Functional Theory and Strong
    Interactions: Orbital Ordering in Mott-Hubbard Insulators”, Phys. Rev. B 52, R5467
    (1995).
    [15] S. L. Dudarev, G. A. Botton, S. Y. Savrasov, C. J. Humphreys and A. P. Sutton, ”Electron-
    Energy-Loss Spectra and The Structural Stability of Nickel Oxide:An LSDA+U Study”,
    Phys. Rev. B 57, 1505 (1998).
    [16] H. Bethe, ”Splitting of Terms in Crystals”, Ann. Physik 3, 133 (1929).
    [17] J. H. Van Vleck, ”Theory of The Variations in Paramagnetic Anisotropy Among Different
    Salts of The Iron Group”, Phys. Rev. 41, 208 (1932).
    [18] H. A. Jahn and E. Teller, ”Stability of polyatomic Molecules in Degenerate Electronic
    States. I. Orbital Degeneracy”, Proc. Roy. Soc. A 161, 220 (1937).
    [19] J. Springborg and C. E. Schaffer, ”Tetrakis (pyridine) Cobalt(III) Complexes”, Acta. Chem.
    Scand. 27, 3312 (1973).
    [20] L. D. Landau and E. M. Lifshitz, Electrodynamics of continuous media (Fizmatgiz,
    Moscow, 1959).
    [21] E. Ascher, H. Rieder, H. Schmid and H. Stossel, ”Some Properteis of Ferromagnetoelectric
    Nickel-Iodine Boracite, Ni3B7O13I”, J. Appl. Phys. 37, 1404 (1966).
    [22] 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. Rabe, M. Wuttig
    and R. Ramesh, ”Epitaxial BiFeO3 Multiferroic Thin Film Heterostructures”, Science 299,
    1719 (2003).
    [23] N. Hur, S. Park, P. A. Sharma, J. S. Ahn, S. Guha and S-W. Cheong, ”Electric Polarization
    Reversal and Memory in A Multiferroic Material Induced by Magnetic Fields”, Nature
    429, 392 (2004).
    [24] T. Kimura, T. Goto, H. Shintani, K. Ishizaka, T. Arima and Y. Tokura, ”Magnetic Control
    of Ferroelectric Polarization”, Nature 426, 55 (2003).
    [25] G. Toulouse, ”Theory of The Frustration Effect in Spin Glasses I”, Commun. Phys. 2, 115
    (1977).
    [26] J. Vannimenus and G. Toulouse, ”Theory of The Frustration Effect. II. Ising Spins on A
    Square Lattice”, J. Phys. C: Solid State Phys. 10, L537 (1977).
    [27] G. H. Wannier, ”Antiferromagnetism. The Triangular Ising Net”, Phys. Rev. 79, 357
    (1950).
    [28] L. Pauling, ”The Structure and Entropy of Ice and of Other Crystals with Some Randomness
    of Atomic Arrangement”, J. Am. Chem. Soc. 57 2680 (1935).
    [29] N. A. Hill, ”Why Are There so Few Magnetic Ferroelectrics?”, J. Phys. Chem. B 104, 6694
    (2000).
    [30] D. I. Khomskii, ”Multiferroics: Different Ways to Combine Magnetism and Ferroelectricity”,
    J. Magn. Magn. Mater. 306, 1 (2006).
    [31] D. V. Efremov, J. van den Brink, and D. I. Khomskii, ”Bond-Versus Site-Centred Ordering
    and Possible Ferroelectricity in Manganites”, Nature Mater. 3, 853 (2004).
    [32] B. B. Van Aken, T. T. M. Palstra, A. Filippetti and N. A. Spaldin, ”The Origin of Ferroelectricity
    in Magnetoelectric YMnO3”, Nature Mater. 3, 164 (2004).
    [33] D. Khomskii, ”Classifying Multiferroics: Mechanisms and Effects”, Physics 2, 20 (2009).
    [34] H. Katsura, N. Nagaosa and A. V. Balatsky, ”Spin Current and Magnetoelectric Effect in
    Noncollinear Magnets”, Phys. Rev. Lett. 95, 057205 (2005).
    [35] M. V. Mostovoy, ”Ferroelectricity in Spiral Magnets”, Phys. Rev. Lett. 96, 067601 (2006).
    [36] M. Fiebig, ”Revival of The Magnetoelectric Effect”, J. Phys. D 38, R123 (2005).
    [37] H. Kuroe, T. Hosaka, S. Hachiuma, T. Sekine, M. Hase, K. Oka, T. Ito, H. Eisaki, M.
    Fujisawa, S. Okubo and H. Ohta, ”Electric Polarization Induced by Neel Order without
    Magnetic Superlattice: Experimental Study of Cu3Mo2O9 and Numerical Study of A Small
    Spin Cluster”, J. Phys. Soc. Jpn. 80, 083705 (2011).
    [38] S. Vilminot, G. Andre and M. Kurmoo, ”Magnetic Properties and Magnetic Structure of
    Cu3Mo2O9”, Inorg. Chem, 48, 2687 (2009).
    [39] T. Hamasaki, T. Ide, H. Kuroe and T. Sekine, ”Successive Phase Transitions to Antiferromagnetic
    and Weak-Ferromagnetic Long-Range Order in The Quasi-One-Dimensional
    Antiferromagnet Cu3Mo2O9”, Phys. Rev. B 77, 134419 (2008).
    Description: 碩士
    國立政治大學
    應用物理研究所
    99755007
    101
    Source URI: http://thesis.lib.nccu.edu.tw/record/#G0099755007
    Data Type: thesis
    Appears in Collections:[應用物理研究所 ] 學位論文

    Files in This Item:

    File SizeFormat
    500701.pdf2301KbAdobe PDF1970View/Open


    All items in 政大典藏 are protected by copyright, with all rights reserved.


    社群 sharing

    著作權政策宣告
    1.本網站之數位內容為國立政治大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,惟仍請適度,合理使用本網站之內容,以尊重著作權人之權益。商業上之利用,則請先取得著作權人之授權。
    2.本網站之製作,已盡力防止侵害著作權人之權益,如仍發現本網站之數位內容有侵害著作權人權益情事者,請權利人通知本網站維護人員(nccur@nccu.edu.tw),維護人員將立即採取移除該數位著作等補救措施。
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback