多铁Bi_（1-x）La_x （Mn_（1-y）Fe_y）O_3的结构与电磁性能研究
|
摘要
多铁性材料是一类同时具有两种或两种以上单一铁性(如铁磁-反铁磁性,铁电-反铁电性,及铁弹性)的材料,而且不同铁性之间的耦合协同作用可产生一些新奇的效应,例如,磁化强度和自发极化之间的磁电耦合效应,这些多功能特性为多铁性材料在电子器件等领域开启新的应用前景。在众多的多铁性材料中,BiMnO3因同时具有铁磁性和铁电性而备受人们关注。然而,因Bi基化合物的不稳定性和易挥发性,使得很难实现单一钙钛矿相的BiMnO3,另一方面,BiMnO3具有较低的铁磁转变温度Tc和室温下的高漏导性,这些都极大地限制了BiMnO3可能的应用。
本文采用溶胶-凝胶法制备了多铁性Bi1-xLaxMnO3和Bi0.8La0.2Mn1-xFexO3陶瓷样品材料,研究了烧结温度对Bi1-xLaxMnO3样品钙钛矿相的影响,从而得到了制备单一钙钛矿相Bi1-xLaxMnO3的最佳烧结温度为一窄小的温区(925-950℃),并在此基础上研究了La掺杂对Bi1-xLaxMnO3的结构和磁性能影响。最后在确定最佳烧结温度和La掺杂含量之后,进一步研究了在Mn位掺杂Fe对Bi0.8La0.2Mn1-xFexO3样品的结构与电磁性能的影响。
全文分为四章,各章的主要内容可概括如下：
第一章本章简单回顾了多铁性材料的研究及其进展,介绍了单相多铁材料匮乏的原因和几种实现铁电铁磁共存的机制。重点介绍了BiMnO3的结构和电磁性能,在此基础上,介绍了目前BiMnO3研究中面临的一些问题,并根据相关文献提出了一些可能提高BiMnO3电磁性能的方法与方案。
第二章本章主要介绍了本论文中Bi1-xLaxMnO3和Bi0.8La0.2Mn1-xFexO3样品的制备和测试表征等方法,并对每次测试的实验细节和仪器做了简要的说明。
第三章本章研究了烧结温度和La掺杂依赖的Bi1-xLaxMnO3(BLMO,0.1≤x≤0.4)样品的结构和磁性能,我们的结果显示存在一个窄小的温度区间(925-950℃),在此温度区间烧结的BLMO具有稳定的钙钛矿相。随着La掺杂减少,样品中BLMO钙钛矿相减弱,铁磁转变温度(Tc)由53K降至41K,而饱和磁化强度经历了先降低再升高的变化。这可归因于La含量较少的样品中Bi空位浓度的增加诱导了Mn-O-Mn键角的减小和局域Mn4+离子的增多,使得Mn3+和Mn4+离子的铁磁超交换增强和Mn?+离子的dz2轨道有序受到局域破坏。
第四章在最佳烧结温度和La掺杂的条件下,本章我们研究了在B位掺杂Fe对Bi0.8La0.2Mn1-xFexO3(BLMFO,0≤x≤0.9)样品的结构和电磁性能的影响。XRD测试显示x=0,0.1的样品的结构具有正交对称性,而x=0.3-0.9的样品的结构则具有四方对称性,研究发现样品的磁性能与其单胞结构有强烈的依赖关系。M-T曲线和M-H曲线测量显示出样品的磁相为：x=0,0.1的样品为FM态,随Fe含量x值的增加,样品的发生FM-AFM转变,x=0.3-0.9的样品表现出FM-AFM共存的磁特征。另外,P-E曲线测量表明样品的铁电性随Mn含量的增加逐渐减弱,这归因于过量的Mn离子会导致样品中Fe2+离子含量的增加,从而增加样品的漏导。
One particular current interest is multiferroic materials in which two or three ferroic properties, namely, ferroelectricity(FE), ferromagnetism(FM), and ferroelasticity coexist in the same phase. Particularly, the combination of ferromagnetism and ferroelectricity with coupling between the spontaneous polarization and the magnetization through the magnetoelectric(ME) effect, because they can support novel functionalities in electronic devices. Multiferroic BiMnO3 has been widely renewed interest because BiMnO3 exhibits ferroelectricity and ferromagnetism ordering simultaneously. However, because of the high volatility of Bi for numerous Bi-based compounds, it is difficulty in preparing single perovskite BiMnO3. On the other hand, BiMnO3 also can't support the applications because it's low Curie temperature(Tc) for the ferromagnetic property and high leakage current at roomtemperature(RT).
In this thesis, Multiferroic Bi1-xLaxMnO3 and Bi0.8La0.2Mn1-xFexO3 ceramics samples were synthesized by the sol-gel method. The sintering temperature influence on the perovskite phase of Bi1-xLaxMnO3 samples was carefully studied, it is shown that there was a narrow range of sintering temperature(900～950℃) for the stable perovskite BLMO sample. On this basis, it was carefully investigated that the La doping effect on the structural and magnetic properties of the Bi1-xLaxMnO3 samples sintered at 950℃. And then, the Fe doping effect on the structural and electromagnetic properties of the Bi0.8La0.2Mn1-xFexO3 samples sintered at 950℃was also carefully studied.
The whole thesis consists of four chapters, the main contents in each chapter are presented as follows:
Chapter 1:The general review of the history and present research situation of the multiferroic materials. We make a brief introduction to the reasons for lack of single-multiferrioc materials and several mechanisms for the coexistence of the ferroelectricity and ferromagnetism. And then, we particularly introduced the structure and electromagnetic properties of BiMnO3. On this basis, we introduced several problems in research of BiMnO3, and then we brought out several methods to improve the electromagnetic properties of BiMnO3 by the relevant literature.
Chapter 2:The Bi1-xLaxMnO3 and Bi0.8La0.2Mn1-xFexO3 ceramics preparation methods and the samples measurement methods are introduced, especially the details and instruments of each experimental are introduced.
Chapter 3:The sintering temperature influence on the perovskite phase of Bi1-xLaxMnO3 samples was carefully studied by using X-ray diffraction (XRD), scanning electronic microscope (SEM), fourier transformation infrared spectroscopy(FT-IR), and the thermo gravimetric analysis-differential thermal analyses (TG-DTA). It was also carefully investigated that the La doping effect on the structural and magnetic properties of the BLMO samples sintered at 950℃. Our results indicated that the perovskite phase of samples was weakened as La doping reducing, the Curie temperature Tc decrease from 53K to 41K, corresponding to the saturation magnetization experienced a lowering and then an enhancing. It was ascribed to the increase of Bi vacancies in La doping reducing samples, which induced a decrease of Mn-O-Mn bond angle and an increase of Mn4+ ions. This resulted in an enhancing of the ferromagnetic superexchange between Mn3+ and Mn4+ ions and a disrupting of the dz2 orbital ordering around the Mn3+ matrix.
Chapter 4:The structural, magnetization, and electrical properties of Bio.8Lao.2Mn1-xFexO3 samples were carefully investigated. It was found samples with x=0,0.1 shown a distorted orthorhombic crystal structure, and a distorted tetragonal crystal structure for x≥0.3, and we also found a clear correlation between the magnetization and the crystal structure. A magnetic transition from a ferromagnetic (FM) state (x=0,0.1) to a antiferromagneic (AFM) state (x≥0.3) with increasing Fe content, and the samples had a competition between FM and AFM at room temperature for x≥0.3 were observed by M-T and M-H curves. Compared the polarization hysteresis loops of the sample for x=0.9 and x=0.7, it is seen with decreasing x, the samples have a higher leakage current, which leading to the weakened ferroelectric(FE). It was ascribed to that excessive Mn-doped in Bi0.8La0.2MnxFe1-xO3 system can increase the ratio of Fe2+/Fe3+, which weaken the ferroelectric.
本文采用溶胶-凝胶法制备了多铁性Bi1-xLaxMnO3和Bi0.8La0.2Mn1-xFexO3陶瓷样品材料,研究了烧结温度对Bi1-xLaxMnO3样品钙钛矿相的影响,从而得到了制备单一钙钛矿相Bi1-xLaxMnO3的最佳烧结温度为一窄小的温区(925-950℃),并在此基础上研究了La掺杂对Bi1-xLaxMnO3的结构和磁性能影响。最后在确定最佳烧结温度和La掺杂含量之后,进一步研究了在Mn位掺杂Fe对Bi0.8La0.2Mn1-xFexO3样品的结构与电磁性能的影响。
全文分为四章,各章的主要内容可概括如下：
第一章本章简单回顾了多铁性材料的研究及其进展,介绍了单相多铁材料匮乏的原因和几种实现铁电铁磁共存的机制。重点介绍了BiMnO3的结构和电磁性能,在此基础上,介绍了目前BiMnO3研究中面临的一些问题,并根据相关文献提出了一些可能提高BiMnO3电磁性能的方法与方案。
第二章本章主要介绍了本论文中Bi1-xLaxMnO3和Bi0.8La0.2Mn1-xFexO3样品的制备和测试表征等方法,并对每次测试的实验细节和仪器做了简要的说明。
第三章本章研究了烧结温度和La掺杂依赖的Bi1-xLaxMnO3(BLMO,0.1≤x≤0.4)样品的结构和磁性能,我们的结果显示存在一个窄小的温度区间(925-950℃),在此温度区间烧结的BLMO具有稳定的钙钛矿相。随着La掺杂减少,样品中BLMO钙钛矿相减弱,铁磁转变温度(Tc)由53K降至41K,而饱和磁化强度经历了先降低再升高的变化。这可归因于La含量较少的样品中Bi空位浓度的增加诱导了Mn-O-Mn键角的减小和局域Mn4+离子的增多,使得Mn3+和Mn4+离子的铁磁超交换增强和Mn?+离子的dz2轨道有序受到局域破坏。
第四章在最佳烧结温度和La掺杂的条件下,本章我们研究了在B位掺杂Fe对Bi0.8La0.2Mn1-xFexO3(BLMFO,0≤x≤0.9)样品的结构和电磁性能的影响。XRD测试显示x=0,0.1的样品的结构具有正交对称性,而x=0.3-0.9的样品的结构则具有四方对称性,研究发现样品的磁性能与其单胞结构有强烈的依赖关系。M-T曲线和M-H曲线测量显示出样品的磁相为：x=0,0.1的样品为FM态,随Fe含量x值的增加,样品的发生FM-AFM转变,x=0.3-0.9的样品表现出FM-AFM共存的磁特征。另外,P-E曲线测量表明样品的铁电性随Mn含量的增加逐渐减弱,这归因于过量的Mn离子会导致样品中Fe2+离子含量的增加,从而增加样品的漏导。
One particular current interest is multiferroic materials in which two or three ferroic properties, namely, ferroelectricity(FE), ferromagnetism(FM), and ferroelasticity coexist in the same phase. Particularly, the combination of ferromagnetism and ferroelectricity with coupling between the spontaneous polarization and the magnetization through the magnetoelectric(ME) effect, because they can support novel functionalities in electronic devices. Multiferroic BiMnO3 has been widely renewed interest because BiMnO3 exhibits ferroelectricity and ferromagnetism ordering simultaneously. However, because of the high volatility of Bi for numerous Bi-based compounds, it is difficulty in preparing single perovskite BiMnO3. On the other hand, BiMnO3 also can't support the applications because it's low Curie temperature(Tc) for the ferromagnetic property and high leakage current at roomtemperature(RT).
In this thesis, Multiferroic Bi1-xLaxMnO3 and Bi0.8La0.2Mn1-xFexO3 ceramics samples were synthesized by the sol-gel method. The sintering temperature influence on the perovskite phase of Bi1-xLaxMnO3 samples was carefully studied, it is shown that there was a narrow range of sintering temperature(900～950℃) for the stable perovskite BLMO sample. On this basis, it was carefully investigated that the La doping effect on the structural and magnetic properties of the Bi1-xLaxMnO3 samples sintered at 950℃. And then, the Fe doping effect on the structural and electromagnetic properties of the Bi0.8La0.2Mn1-xFexO3 samples sintered at 950℃was also carefully studied.
The whole thesis consists of four chapters, the main contents in each chapter are presented as follows:
Chapter 1:The general review of the history and present research situation of the multiferroic materials. We make a brief introduction to the reasons for lack of single-multiferrioc materials and several mechanisms for the coexistence of the ferroelectricity and ferromagnetism. And then, we particularly introduced the structure and electromagnetic properties of BiMnO3. On this basis, we introduced several problems in research of BiMnO3, and then we brought out several methods to improve the electromagnetic properties of BiMnO3 by the relevant literature.
Chapter 2:The Bi1-xLaxMnO3 and Bi0.8La0.2Mn1-xFexO3 ceramics preparation methods and the samples measurement methods are introduced, especially the details and instruments of each experimental are introduced.
Chapter 3:The sintering temperature influence on the perovskite phase of Bi1-xLaxMnO3 samples was carefully studied by using X-ray diffraction (XRD), scanning electronic microscope (SEM), fourier transformation infrared spectroscopy(FT-IR), and the thermo gravimetric analysis-differential thermal analyses (TG-DTA). It was also carefully investigated that the La doping effect on the structural and magnetic properties of the BLMO samples sintered at 950℃. Our results indicated that the perovskite phase of samples was weakened as La doping reducing, the Curie temperature Tc decrease from 53K to 41K, corresponding to the saturation magnetization experienced a lowering and then an enhancing. It was ascribed to the increase of Bi vacancies in La doping reducing samples, which induced a decrease of Mn-O-Mn bond angle and an increase of Mn4+ ions. This resulted in an enhancing of the ferromagnetic superexchange between Mn3+ and Mn4+ ions and a disrupting of the dz2 orbital ordering around the Mn3+ matrix.
Chapter 4:The structural, magnetization, and electrical properties of Bio.8Lao.2Mn1-xFexO3 samples were carefully investigated. It was found samples with x=0,0.1 shown a distorted orthorhombic crystal structure, and a distorted tetragonal crystal structure for x≥0.3, and we also found a clear correlation between the magnetization and the crystal structure. A magnetic transition from a ferromagnetic (FM) state (x=0,0.1) to a antiferromagneic (AFM) state (x≥0.3) with increasing Fe content, and the samples had a competition between FM and AFM at room temperature for x≥0.3 were observed by M-T and M-H curves. Compared the polarization hysteresis loops of the sample for x=0.9 and x=0.7, it is seen with decreasing x, the samples have a higher leakage current, which leading to the weakened ferroelectric(FE). It was ascribed to that excessive Mn-doped in Bi0.8La0.2MnxFe1-xO3 system can increase the ratio of Fe2+/Fe3+, which weaken the ferroelectric.
引文
[1]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[2]王克锋,刘俊明,王雨.单相多铁性材料—极化和磁性序参量的耦合和调控[J],科学通报,2008,53：1098-1135.
[3]Wolf S A, Awschalom D D, Buhrman R A, et al. A spin-based electronics vision for the future[J]. Science,2001,294:1488-1490.
[4]Zutic I, Fabian J, Das Sarma S. Fundamentals and applications[J]. Rev Mod Phys,2004,76: 323-410.
[5]Scott J F. Ferroelectric Memories[M]. Berlin:Springer-Verlag,2000.
[6]Le Bras G, Colson D, Forget A, et al. Magnetization and magnetoelectric effect in Bi1-xLaxFeO3 (0≤x≤0.15)[J]. Phys Rev B,2009,80:134417.
[7]Schmid. H. Multi-ferroic magneto electrics [J]. Ferroelectrics,1994,162:317-338.
[8]Ce-Wen Nan, Gang Liu, Yuanhua lin. Magnetic-Field-Electric Polarization in MultiferroicNanostructures [J]. Phys. Rev. Lett.,2005,94(19):197203:1-4.
[9]路晓艳,刘玉岚,王彪.。多重铁性材料的研究进展.[J].材料导报,2007,21(3)：17-20.
[10]Khomskii D I. Different ways to combine magnetism and ferroelectricity[J]. J Magn Magn Mater,2006,306:1-8
[11]迟振华,靳常青.单相磁电多铁性体研究进展[J].物理学进展,2007,27：225-238
[12]Cheong S W, Mostovoy M. A magnetic twist for ferroelectricity[J]. Nature Mater,2007,6: 13-20
[13]Ramesh R, Spaldin A N. Progress and prospects in thin films[J]. Nature Mater,2007,6: 21-29.
[14]Schmid H. Magnetic ferroelectric materials[J]. Bull Mater Sci,2007,17:1411-1414
[15]Ascher E, Rieder H, Schmid H, et, al. Some properties of Ferromagnetoelectric Nickel-Iodine Boracite Ni3B7O13I[J].J. Appl. Phys.,1966,37:1404-1405.
[16]Schmid H. Ferroelectrics,1994,162:265.
[17]Aizu.K. Possible species of ferromagnetic, ferroelectric, and ferroelastic crystal[J]. Phys.Rev. B,1970,2(3):754-772.
[18]Wang J, Neaton J B, Zheng H, et al. Epitaxial BiFeO3 multiferroic thin film heterostructures[J]. Science,2003,299(5613):1719-1722.
[19]Rado G T, Folen V. Observation of the magnetically induced magnetoelectric effect and evidence for antiferromagnetic domains[J]. Phys Rev Lett,1961,7:310-311.
[20]Fiebig M. Revival of the magnetoelectric effect [J]. J Phys D:Appl Phys,2005,38: R123-R152.
[21]Zhang H, Wang J, Lofland S E, et al. Multiferroic BaTiO3-CoFe2O4 nanostructure[J]. Science, 2003,83:4812-4814.
[22]Lines M E, Glass A. Principle and Application of Ferroelectric and Related Materials[M]. Oxford:Oxford University Press,2001.
[23]Eerenstein W, Mathur N D, Scott J F. Multiferroic and magnetoelectric materials[J]. Nature, 2006,442(7104):759-765.
[24]Cohen R E. Origin of ferroelectricity in perovskite oxides[J]. Nature,1992,358:136-138.
[25]Brunskill I H, Depmeier W. High temperature solution growth of Pb(Fe1/2Nb1/2)O3 and Pb(Mn1/2Nb1/2)O3[J]. J Cryst Growth,1981,56:541-546.
[26]Vokov V A. Ferroelectric antiferromagnetics[J]. Sov Phys JETP,1962,15:447-451.
[27]Ivanov S A, Rundlof H. Investigation of the structure of the relaxor ferroelectric Pb(Fe1/2Nb1/2)O3 by neutron powder diffraction [J]. J Phys:Cond Matt,2000,12:2393-2400.
[28]Cohen R E. Origin of ferroelectricity in perovskite oxides[J]. Nature,1992,358(6382): 136-138.
[29]Wu Z G, Cohen R E. Pressure-induced anomalous phase transitions and colossal enhancement of piezoelectricity in PbTiO3[J]. Phys Rev L,2005,95(3):036601.
[30]Trinquier G, Hoffman J R. Lead monoxide. Electronic structure and bonding[J]. J Phys Chem, 1984,88:6696-6711.
[31]Waston G W, Parker S C. Ab initio calculation of the origin of the distortion of a-PbO[J]. Phys Rev B,1999,59:8481-8486.
[32]Seshadri R, Hill N A. Visualizing the role of Bi 6s "Lone Pairs" in the off-center distortion in ferromagnetic BiMnO3[J]. Chem Mater,2001,13:2892-2899.
[33]Ederer C, Spaldin N A. Recent progress in first-principles studies of magnetoelectric multiferroics[J]. Current Opinion in Solid State & Materials Science,2006,9(3):128-139.
[34]Mostovoy M. Ferroeletricity in spiral magnets[J]. Phys Rev L,2006,96(6):067601.
[35]Fischer P, Sosnowska I. Temperature dependence of the crystal and magnetic structure of BiFeO3[J]. J Phys C,1980,13:1931.
[36]Lebeugle D, Colson D, Forget A, et al. Very large spontaneous electric polarization in BiFeO3 single crystals at room temperature and its evolution under cycling fields[J]. Appl Phys Lett,2007,91:022907.
[37]Tsai M H, Tsang Y H, Dey S K. Co-existence of ferroelectricity and ferromagnetism in 1.4 nm SrBi2Ta2O11 film[J]. J Phys:Cond Matter,2005,15:7901-7915.
[38]Aton T, Chiba H, Ohoyama K. Structure determination of ferromagnetic perovskite BiMnO3[J]. J Solid State Chem,1999,145:639-642.
[39]Kimura T, Kawamoto S, Yamada I, et al. Magnetocapacitance effect in multiferroic BiMnO3[J]. Phys Rev B,2003,67:180401.
[40]H. Chiba, T. Atou, and Y. Syono Magnetic and Electrical Properties of Bi1-xSrxMnO3: Hole-Doping Effect on Ferromagnetic Perovskite BiMnO3 [J]. J. Solid State Chem.1997,132, 139-143.
[41]Seshadri R, Hill N A. Visualizing the role of Bi 6s "Lone Pairs" in the off-center distortion in ferromagnetic BiMnO3[J]. Chem Mater,2001,13:2892-2899.
[42]Chiba H, Atou T, Syono Y. Magnetic and electric properties of Bi1-xSrxMnO3:Hole-doping effect on ferromagnetic perovskite BiMnO3[J]. J Solid State Chem.1997,132:139-143.
[43]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[44]Chou C C, Huang C L, Mukherjee S, et al. Multiple magnetic transitions in multiferroic BiMnO3[J]. PHYSICAL REVIEW B,2009,80:184426.
[45]Belik A A, Kolodiazhnyi T, Kosuda K, and Takayama-Muromachi E. Synthesis and properties of oxygen non-stoichiometric BiMnO3[J]. J. Mater. Chem.2009,19:1593.
[46]Yang C H, Koo T Y, Lee S H, Song C,. Lee K B, and Jeong Y H. Orbital Ordering and Enhanced Magnetic Frustration of Strained BiMnO3 Thin Films[J]. Europhys. Lett.2006,74: 348.
[47]Grizalez M, Mendoza G A, Prieto P. Analysis of multiferroic properties in BiMnO3 thin films[J]. Journal of Physics:Conference Series,2009,167:012035.
[48]Ohshima E, Saya Y, Nantoh M, and Kawai M. Solid State Commun.2000,116:73.
[49]Yang C H, Koo T Y, Lee S H, et al. Orbital Ordering and Enhanced Magnetic Frustration of Strained BiMnO3 Thin Films[J]. Europhys. Lett.,2006,74:348.
[50]Valasek J. Phys. Rev.1921,17:475.
[51]Ravindran P, Vidya R, Kjekshus A, and Fjellvag H. Theoretical investigation of magnetoelectric behavior in BiFeO3[J]. Phys. Rev. B 74,224412 (2006).
[52]Moreira dos Santos A, Parashar S, Raju A R, Zhao Y S, Cheetham A K, andRao C N R. Evidence for the likely occurrence of magneto ferroelectricity in the simple perovskite, BiMnO3 [J], Solid State Commun.2002,122,49-52.
[53]Son J Y, Park C S, and Hyungjun Kim. Room Temperature Ferroelectric Property of BiMnO3 Thin Film with Double SrTiO3 Buffer Layers on Pt/Ti/SiO2/Si Substrate[J]. Met. Mater. Int.,2010,16(2):289-292.
[54]Fiebig M. Revival of the magnetoelectric effect[J]. J Phys D:Appl Phys,2005,38: R123-R152.
[55]Zhang S T, Lu M H, Wu D, et al. Large polarization and weak ferromagnetism in quenched BiFeO3 ceramics with a distorted rhombohedral crystal structure[J]. Appl Phys Lett,2005, 87:262907.
[56]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[57]Lee Y H, Liang C S, Wu J M. Growth and characterization of highly oriented BiFeO3 thin films[J]. Electrochem. Solid-State Lett.2005,8:F55.
[58]Ternon C, Thery J, Baron T, Ducros C, Sanchette F, Kreisel J. MOCVD of BiFeO3 thin films on SrTiO3[J]. Thin Solid Films,2006,515:481.
[59]Das R R, Kim D M, Baek S H, Eom C B, et al. Synthesis and ferroelectric properties of epitaxial BiFeO3 thin films grown by sputtering[J]. Appl. Phys. Lett.,2006,88:242904.
[60]Zheng R Y, Gao X S, Zhou Z H, Wang J. Multiferroic BiFeO3 thin films deposited on SrRuO3 buffer layer by rf sputtering[J]. J. Appl. Phys.2007,101:054104.
[61]Xiaoding Qi, Po-Chou Tsai, Yi-Chun Chen, Cheng-Hung Ko,Jung-Chun-Andrew Huang and In-Gann Chen. Ferroelectric properties and dielectric responses of multiferroic BiFeO3 films grown by RF magnetron sputtering[J]. J. Phys. D:Appl. Phys.2008,41:23200.
[62]X. D. Qi, J. H. Dho, M. Blamire, Q. X. Jia, J.S. Lee, S. Foltyn, L. Judith, MacManus-Driscoll, J. Mag. Magnetic Mater.2004,283,415-421.
[63]Thery J, Dubourdieu C, Baron T, et al. MOCVD of BiFeO3 thin films on SrTiO3[J]. Chem. Vap. Deposition,2007,13:232-238.
[64]Srinivas A, Kim D W, and Hong K S. Observation of ferroelectromagnetic nature in rare-earth-substituted bismuth iron titanate [J]. Appl. Phys. Lett.,2003,83, (11)2217:1-3.
[65]Yau C Y, Palan R, Tran K, Buchanan RC. Appl. Phys. Lett.86,032907(2005).
[66]吴振名,行政院国家科学委员会专题研究计划书期中进度报告[R].北京：清华大学材料科学工程学系,1995.
[67]Troyanchuk I O, Mantytskaja O S, Szymczak H, Shvedun M Yu. Magnetic phase transitions in the system La1-xBixMnO3-λ[J]. Low. Temp. Phys.,2002,28:569-573.
[68]Gajek M, Bibes M, Fusil S, et al. Tunnel junctions with multiferroic barriers[J]. Nature Materials,2007,6:296-302.
[69]Singh S K, Maruyama K, Ishiwara H. Reduced leakage current in La and Ni codoped BiFeO3 thin films[J]. Appl. Phys. Lett.91,112913 (2007).
[70]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[71]PalovaL, Chandra P, Rabe K M. Multiferroic BiFeO3-BiMnO3 nanoscale checkerboard from first principles[J]. Phys. Rev. B,2010,82:075432.
[1]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[2]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[3]Yau C Y, Palan R, Tran K, Buchanan RC. Appl. Phys. Lett.86,032907(2005).
[1]Troyanchuk I O, Mantytskaja O S, Szymczak H, et al. Magnetic phase transitions in the system La1-xBixMnO3-λ[J]. Low Temp Phys,2002,28(7):569-573.
[2]刘石明,邢长生,钱晓良La0.8Sr0.2Co0.5Fe0.5O3纳米粉料的制备与表征[J].华中科技大学学报,2005,33(1)：81-83.
[3]Cao S, Ma Y Q, Quan C M, et al. Photoluminescence properties of Ca9Y(VO4)7 and Ca9Y0.95Ln0.05(VO4)7(Ln3+=Eu3+, Sm3+, Pr3+)[J]. JAlloys Compd,2009,487:346-350.
[4]董晓伟,金绍维,李爱侠,等.烧结温度对多铁Bi0.6La0.4MnO3陶瓷钙钛矿相的影响[J].安徽大学学报：自然科学版,2010,34(6)：53-57.
[5]Shannon R D, Prewitt C T. Effective ionic radii in oxides and fluorides[J]. Acta Crystallogr, Sect. B:Struct. Crystallogr. Cryst. Chem B,25 (1969),925.
[6]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[7]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[8]T. Atou, H. Chiba, K. Ohoyama, Y. Yamagnuchi, and Y. Syono, J. Solid. State. Chem.145 (1999),639.
[9]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[1]Belik A A, Kolodiazhnyi T, Kosuda K, and Takayama-Muromachi E. Synthesis and properties of oxygen non-stoichiometric BiMnO3[J]. J. Mater. Chem.2009,19:1593.
[2]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[3]PalovaL, Chandra P, Rabe K M. Multiferroic BiFeO3-BiMnO3 nanoscale checkerboard from first principles[J]. Phys. Rev. B,2010,82:075432.
[4]訾玉宝,焦兴利,王海峰,刘亲壮,殷志珍,张福恒,黄振,吴文彬.Mn掺杂对多铁性BiFeO3薄膜铁电性能以及漏电流的影响[J].低温物理学报,2009,34：4.
[5]Pradhan A K, Zhang Kai, Hunter D, Dadson J B, Loutts G B, et al. Magnetic and electrical properties of single-phase multiferroic BiFeO3[J]. JOURNAL OF APPLIED PHYSICS,2005, 97:093903.
[6]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[7]Chen F, and Zhang Q F, Sol-gel Derived Multiferroic BiFeO3 Ceramics With Large Polarization and Weak Ferromagnetism[J]. Appl. Phys. Lett.,2006,89:092910.
[8]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[9]Zhang S T, Lu M H, Wu D, et al. Large polarization and weak ferromagnetism in quenched BiFeO3 ceramics with a distorted rhombohedral crystal structure[J]. Appl Phys Lett,2005, 87:262907.
[10]Singh S K, Menou N, Funakubo H, Maruyama K, and Ishiwara H, Appl. Phys. Lett.90, 242914 (2007).
[11]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[12]Lankhim V, Skuimryer V, Matri X, et al. Electric-field control of exchange bias in multiferroic epitaxial heterostructures[J]. Phys Rev Lett,2006,97:227201.
[2]王克锋,刘俊明,王雨.单相多铁性材料—极化和磁性序参量的耦合和调控[J],科学通报,2008,53：1098-1135.
[3]Wolf S A, Awschalom D D, Buhrman R A, et al. A spin-based electronics vision for the future[J]. Science,2001,294:1488-1490.
[4]Zutic I, Fabian J, Das Sarma S. Fundamentals and applications[J]. Rev Mod Phys,2004,76: 323-410.
[5]Scott J F. Ferroelectric Memories[M]. Berlin:Springer-Verlag,2000.
[6]Le Bras G, Colson D, Forget A, et al. Magnetization and magnetoelectric effect in Bi1-xLaxFeO3 (0≤x≤0.15)[J]. Phys Rev B,2009,80:134417.
[7]Schmid. H. Multi-ferroic magneto electrics [J]. Ferroelectrics,1994,162:317-338.
[8]Ce-Wen Nan, Gang Liu, Yuanhua lin. Magnetic-Field-Electric Polarization in MultiferroicNanostructures [J]. Phys. Rev. Lett.,2005,94(19):197203:1-4.
[9]路晓艳,刘玉岚,王彪.。多重铁性材料的研究进展.[J].材料导报,2007,21(3)：17-20.
[10]Khomskii D I. Different ways to combine magnetism and ferroelectricity[J]. J Magn Magn Mater,2006,306:1-8
[11]迟振华,靳常青.单相磁电多铁性体研究进展[J].物理学进展,2007,27：225-238
[12]Cheong S W, Mostovoy M. A magnetic twist for ferroelectricity[J]. Nature Mater,2007,6: 13-20
[13]Ramesh R, Spaldin A N. Progress and prospects in thin films[J]. Nature Mater,2007,6: 21-29.
[14]Schmid H. Magnetic ferroelectric materials[J]. Bull Mater Sci,2007,17:1411-1414
[15]Ascher E, Rieder H, Schmid H, et, al. Some properties of Ferromagnetoelectric Nickel-Iodine Boracite Ni3B7O13I[J].J. Appl. Phys.,1966,37:1404-1405.
[16]Schmid H. Ferroelectrics,1994,162:265.
[17]Aizu.K. Possible species of ferromagnetic, ferroelectric, and ferroelastic crystal[J]. Phys.Rev. B,1970,2(3):754-772.
[18]Wang J, Neaton J B, Zheng H, et al. Epitaxial BiFeO3 multiferroic thin film heterostructures[J]. Science,2003,299(5613):1719-1722.
[19]Rado G T, Folen V. Observation of the magnetically induced magnetoelectric effect and evidence for antiferromagnetic domains[J]. Phys Rev Lett,1961,7:310-311.
[20]Fiebig M. Revival of the magnetoelectric effect [J]. J Phys D:Appl Phys,2005,38: R123-R152.
[21]Zhang H, Wang J, Lofland S E, et al. Multiferroic BaTiO3-CoFe2O4 nanostructure[J]. Science, 2003,83:4812-4814.
[22]Lines M E, Glass A. Principle and Application of Ferroelectric and Related Materials[M]. Oxford:Oxford University Press,2001.
[23]Eerenstein W, Mathur N D, Scott J F. Multiferroic and magnetoelectric materials[J]. Nature, 2006,442(7104):759-765.
[24]Cohen R E. Origin of ferroelectricity in perovskite oxides[J]. Nature,1992,358:136-138.
[25]Brunskill I H, Depmeier W. High temperature solution growth of Pb(Fe1/2Nb1/2)O3 and Pb(Mn1/2Nb1/2)O3[J]. J Cryst Growth,1981,56:541-546.
[26]Vokov V A. Ferroelectric antiferromagnetics[J]. Sov Phys JETP,1962,15:447-451.
[27]Ivanov S A, Rundlof H. Investigation of the structure of the relaxor ferroelectric Pb(Fe1/2Nb1/2)O3 by neutron powder diffraction [J]. J Phys:Cond Matt,2000,12:2393-2400.
[28]Cohen R E. Origin of ferroelectricity in perovskite oxides[J]. Nature,1992,358(6382): 136-138.
[29]Wu Z G, Cohen R E. Pressure-induced anomalous phase transitions and colossal enhancement of piezoelectricity in PbTiO3[J]. Phys Rev L,2005,95(3):036601.
[30]Trinquier G, Hoffman J R. Lead monoxide. Electronic structure and bonding[J]. J Phys Chem, 1984,88:6696-6711.
[31]Waston G W, Parker S C. Ab initio calculation of the origin of the distortion of a-PbO[J]. Phys Rev B,1999,59:8481-8486.
[32]Seshadri R, Hill N A. Visualizing the role of Bi 6s "Lone Pairs" in the off-center distortion in ferromagnetic BiMnO3[J]. Chem Mater,2001,13:2892-2899.
[33]Ederer C, Spaldin N A. Recent progress in first-principles studies of magnetoelectric multiferroics[J]. Current Opinion in Solid State & Materials Science,2006,9(3):128-139.
[34]Mostovoy M. Ferroeletricity in spiral magnets[J]. Phys Rev L,2006,96(6):067601.
[35]Fischer P, Sosnowska I. Temperature dependence of the crystal and magnetic structure of BiFeO3[J]. J Phys C,1980,13:1931.
[36]Lebeugle D, Colson D, Forget A, et al. Very large spontaneous electric polarization in BiFeO3 single crystals at room temperature and its evolution under cycling fields[J]. Appl Phys Lett,2007,91:022907.
[37]Tsai M H, Tsang Y H, Dey S K. Co-existence of ferroelectricity and ferromagnetism in 1.4 nm SrBi2Ta2O11 film[J]. J Phys:Cond Matter,2005,15:7901-7915.
[38]Aton T, Chiba H, Ohoyama K. Structure determination of ferromagnetic perovskite BiMnO3[J]. J Solid State Chem,1999,145:639-642.
[39]Kimura T, Kawamoto S, Yamada I, et al. Magnetocapacitance effect in multiferroic BiMnO3[J]. Phys Rev B,2003,67:180401.
[40]H. Chiba, T. Atou, and Y. Syono Magnetic and Electrical Properties of Bi1-xSrxMnO3: Hole-Doping Effect on Ferromagnetic Perovskite BiMnO3 [J]. J. Solid State Chem.1997,132, 139-143.
[41]Seshadri R, Hill N A. Visualizing the role of Bi 6s "Lone Pairs" in the off-center distortion in ferromagnetic BiMnO3[J]. Chem Mater,2001,13:2892-2899.
[42]Chiba H, Atou T, Syono Y. Magnetic and electric properties of Bi1-xSrxMnO3:Hole-doping effect on ferromagnetic perovskite BiMnO3[J]. J Solid State Chem.1997,132:139-143.
[43]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[44]Chou C C, Huang C L, Mukherjee S, et al. Multiple magnetic transitions in multiferroic BiMnO3[J]. PHYSICAL REVIEW B,2009,80:184426.
[45]Belik A A, Kolodiazhnyi T, Kosuda K, and Takayama-Muromachi E. Synthesis and properties of oxygen non-stoichiometric BiMnO3[J]. J. Mater. Chem.2009,19:1593.
[46]Yang C H, Koo T Y, Lee S H, Song C,. Lee K B, and Jeong Y H. Orbital Ordering and Enhanced Magnetic Frustration of Strained BiMnO3 Thin Films[J]. Europhys. Lett.2006,74: 348.
[47]Grizalez M, Mendoza G A, Prieto P. Analysis of multiferroic properties in BiMnO3 thin films[J]. Journal of Physics:Conference Series,2009,167:012035.
[48]Ohshima E, Saya Y, Nantoh M, and Kawai M. Solid State Commun.2000,116:73.
[49]Yang C H, Koo T Y, Lee S H, et al. Orbital Ordering and Enhanced Magnetic Frustration of Strained BiMnO3 Thin Films[J]. Europhys. Lett.,2006,74:348.
[50]Valasek J. Phys. Rev.1921,17:475.
[51]Ravindran P, Vidya R, Kjekshus A, and Fjellvag H. Theoretical investigation of magnetoelectric behavior in BiFeO3[J]. Phys. Rev. B 74,224412 (2006).
[52]Moreira dos Santos A, Parashar S, Raju A R, Zhao Y S, Cheetham A K, andRao C N R. Evidence for the likely occurrence of magneto ferroelectricity in the simple perovskite, BiMnO3 [J], Solid State Commun.2002,122,49-52.
[53]Son J Y, Park C S, and Hyungjun Kim. Room Temperature Ferroelectric Property of BiMnO3 Thin Film with Double SrTiO3 Buffer Layers on Pt/Ti/SiO2/Si Substrate[J]. Met. Mater. Int.,2010,16(2):289-292.
[54]Fiebig M. Revival of the magnetoelectric effect[J]. J Phys D:Appl Phys,2005,38: R123-R152.
[55]Zhang S T, Lu M H, Wu D, et al. Large polarization and weak ferromagnetism in quenched BiFeO3 ceramics with a distorted rhombohedral crystal structure[J]. Appl Phys Lett,2005, 87:262907.
[56]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[57]Lee Y H, Liang C S, Wu J M. Growth and characterization of highly oriented BiFeO3 thin films[J]. Electrochem. Solid-State Lett.2005,8:F55.
[58]Ternon C, Thery J, Baron T, Ducros C, Sanchette F, Kreisel J. MOCVD of BiFeO3 thin films on SrTiO3[J]. Thin Solid Films,2006,515:481.
[59]Das R R, Kim D M, Baek S H, Eom C B, et al. Synthesis and ferroelectric properties of epitaxial BiFeO3 thin films grown by sputtering[J]. Appl. Phys. Lett.,2006,88:242904.
[60]Zheng R Y, Gao X S, Zhou Z H, Wang J. Multiferroic BiFeO3 thin films deposited on SrRuO3 buffer layer by rf sputtering[J]. J. Appl. Phys.2007,101:054104.
[61]Xiaoding Qi, Po-Chou Tsai, Yi-Chun Chen, Cheng-Hung Ko,Jung-Chun-Andrew Huang and In-Gann Chen. Ferroelectric properties and dielectric responses of multiferroic BiFeO3 films grown by RF magnetron sputtering[J]. J. Phys. D:Appl. Phys.2008,41:23200.
[62]X. D. Qi, J. H. Dho, M. Blamire, Q. X. Jia, J.S. Lee, S. Foltyn, L. Judith, MacManus-Driscoll, J. Mag. Magnetic Mater.2004,283,415-421.
[63]Thery J, Dubourdieu C, Baron T, et al. MOCVD of BiFeO3 thin films on SrTiO3[J]. Chem. Vap. Deposition,2007,13:232-238.
[64]Srinivas A, Kim D W, and Hong K S. Observation of ferroelectromagnetic nature in rare-earth-substituted bismuth iron titanate [J]. Appl. Phys. Lett.,2003,83, (11)2217:1-3.
[65]Yau C Y, Palan R, Tran K, Buchanan RC. Appl. Phys. Lett.86,032907(2005).
[66]吴振名,行政院国家科学委员会专题研究计划书期中进度报告[R].北京：清华大学材料科学工程学系,1995.
[67]Troyanchuk I O, Mantytskaja O S, Szymczak H, Shvedun M Yu. Magnetic phase transitions in the system La1-xBixMnO3-λ[J]. Low. Temp. Phys.,2002,28:569-573.
[68]Gajek M, Bibes M, Fusil S, et al. Tunnel junctions with multiferroic barriers[J]. Nature Materials,2007,6:296-302.
[69]Singh S K, Maruyama K, Ishiwara H. Reduced leakage current in La and Ni codoped BiFeO3 thin films[J]. Appl. Phys. Lett.91,112913 (2007).
[70]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[71]PalovaL, Chandra P, Rabe K M. Multiferroic BiFeO3-BiMnO3 nanoscale checkerboard from first principles[J]. Phys. Rev. B,2010,82:075432.
[1]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[2]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[3]Yau C Y, Palan R, Tran K, Buchanan RC. Appl. Phys. Lett.86,032907(2005).
[1]Troyanchuk I O, Mantytskaja O S, Szymczak H, et al. Magnetic phase transitions in the system La1-xBixMnO3-λ[J]. Low Temp Phys,2002,28(7):569-573.
[2]刘石明,邢长生,钱晓良La0.8Sr0.2Co0.5Fe0.5O3纳米粉料的制备与表征[J].华中科技大学学报,2005,33(1)：81-83.
[3]Cao S, Ma Y Q, Quan C M, et al. Photoluminescence properties of Ca9Y(VO4)7 and Ca9Y0.95Ln0.05(VO4)7(Ln3+=Eu3+, Sm3+, Pr3+)[J]. JAlloys Compd,2009,487:346-350.
[4]董晓伟,金绍维,李爱侠,等.烧结温度对多铁Bi0.6La0.4MnO3陶瓷钙钛矿相的影响[J].安徽大学学报：自然科学版,2010,34(6)：53-57.
[5]Shannon R D, Prewitt C T. Effective ionic radii in oxides and fluorides[J]. Acta Crystallogr, Sect. B:Struct. Crystallogr. Cryst. Chem B,25 (1969),925.
[6]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[7]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[8]T. Atou, H. Chiba, K. Ohoyama, Y. Yamagnuchi, and Y. Syono, J. Solid. State. Chem.145 (1999),639.
[9]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[1]Belik A A, Kolodiazhnyi T, Kosuda K, and Takayama-Muromachi E. Synthesis and properties of oxygen non-stoichiometric BiMnO3[J]. J. Mater. Chem.2009,19:1593.
[2]H. Woo, T. A. Tyson, M. Croft, S. et al. Phys. Rev. B,2001,63:134412.
[3]PalovaL, Chandra P, Rabe K M. Multiferroic BiFeO3-BiMnO3 nanoscale checkerboard from first principles[J]. Phys. Rev. B,2010,82:075432.
[4]訾玉宝,焦兴利,王海峰,刘亲壮,殷志珍,张福恒,黄振,吴文彬.Mn掺杂对多铁性BiFeO3薄膜铁电性能以及漏电流的影响[J].低温物理学报,2009,34：4.
[5]Pradhan A K, Zhang Kai, Hunter D, Dadson J B, Loutts G B, et al. Magnetic and electrical properties of single-phase multiferroic BiFeO3[J]. JOURNAL OF APPLIED PHYSICS,2005, 97:093903.
[6]Gajek M, Bibes M, Wyczisk F, et al. Growth and magnetic properties of multiferroic LaxBi1-xMnO3 thin films[J]. Phys Rev B,2007,75:174417.
[7]Chen F, and Zhang Q F, Sol-gel Derived Multiferroic BiFeO3 Ceramics With Large Polarization and Weak Ferromagnetism[J]. Appl. Phys. Lett.,2006,89:092910.
[8]Wang Y P, Zhou L, Zhang M F, et al. Room-temperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering[J]. Appl Phys Lett,2004, 84(10):1731-1733.
[9]Zhang S T, Lu M H, Wu D, et al. Large polarization and weak ferromagnetism in quenched BiFeO3 ceramics with a distorted rhombohedral crystal structure[J]. Appl Phys Lett,2005, 87:262907.
[10]Singh S K, Menou N, Funakubo H, Maruyama K, and Ishiwara H, Appl. Phys. Lett.90, 242914 (2007).
[11]Eerenstein W, Morrison F D, Scott J F, et al. Growth of highly resistive BiMnO3 films[J]. Appl. Phys. Lett,2005,87:101906.
[12]Lankhim V, Skuimryer V, Matri X, et al. Electric-field control of exchange bias in multiferroic epitaxial heterostructures[J]. Phys Rev Lett,2006,97:227201.