掺杂铁酸镍陶瓷和复合薄膜的制备以及性能研究
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摘要
铁氧体是一种磁性材料,具有独特的高电阻率和良好的高频特性,被广泛应用在电子、信息、机械等工业领域中,随着电子器件向高性能化和尺寸微型化方向的发展,铁氧体材料受到越来越多的关注,并且已成为当前磁性材料领域研究和开发的重点。NiFe2O4 (NFO)是一种具有多功能用途的铁氧体材料,BaTiO3 (BTO)是一种典型的铁电材料,其在电调谐微波器件有巨大的应用前景。
本文首先采用传统高温固相反应法成功制备了0.45NFO-0.55BTO复合陶瓷。利用复阻抗方法,测试频率从20Hz到2MHz,测试温度为348K至473K,系统地研究了样品的电性能,通过Cole-Cole图,计算了样品的晶粒、晶界电阻值和弛豫时间常数。结果表明,样品的自由电子浓度随温度升高而增加。利用直流电导率的Arrhenius曲线计算了晶粒和晶界的电导率激活能分别为0.32eV和0.38eV,存在这一激活能数值的主要原因是样品中氧空位的迁移,我们也发现弛豫特征频率随着温度升高而升高。另外,样品呈现了典型的磁化曲线,随着测试温度升高,饱和磁化强度(Ms)从2.38emu/g增加到3.13emu/g,矫顽力由0.20e增加到0.70e。
然后我们采用射频磁控溅射法在Si(100)基片上分别制备了NFO薄膜(NFO/Si)和NiFe2O4/La0.7Sr0.3MnO3异质结(NFO/LSMO/Si),研究了LSMO缓冲层对NFO薄膜结构及磁性能的影响。经XRD和扫描电镜(SEM)测试,发现LSMO缓冲层有利于NFO薄膜沿(331)方向择优生长,制备的NFO薄膜的表面是很平整和均匀的。经磁性测试,当薄膜表面与磁场平行时,发现样品在室温下呈现出饱和的磁滞回线,当薄膜表面与磁场垂直时,没有发现任何磁化现象,这表明NFO薄膜平行于磁化方向时存在各向异性。从样品磁滞回线中可以看出,LSMO缓冲层有利于提高NFO薄膜的磁性能,其Ms由41.5 emu/cm3增加到350emu/cm3。
我们也研究了溅射气氛对NFO薄膜结构与磁性能的影响。利用射频磁控溅射法在Si(100)基片上制备了NFO薄膜,溅射气氛包括纯Ar和Ar/O2混合气体。结果表明,在两种不同气氛中沉积的薄膜样品都呈立方尖晶石结构,通入少量氧气之后,薄膜择优取向发生改变,并且磁性能得到改善(Ms为41.5emu/cm3)。
Ferrite materials are widely used in electronics, information, machinery and other industrial areas. Ferrite is a magnetic material has a unique high resistivity and good high frequency characteristics. Those properties have attracted considerable interest in recent years since they might offer the potential to enhance the performance or shrink the dimensional sizes of the microelectronic devices. At present, the ferrite materials are becoming an important research field of the magnetic materials. In the present work, NiFe2O4 (NFO) is one of the most versatile and technologically important ferrite materials. BaTiO3 (BTO) material is a typical ferroelectric material, so it has great application prospect in the electric tuning microwave components.
The standard double sintering ceramic method was used to prepare the 0.45NFO-0.55BTO composite ceramic. Complex impedance spectroscopy of 0.45NFO-0.55BTO composite ceramic on the electrical characteristics were studied. The grain resistance, grain boundary resistance and relaxation time constant were calculated from the Cole-Cole plot. Impedance spectroscopy measurements were conducted in a frequency range from 20 Hz to 2 MHz and in a temperature range from 348 to 473 K. The impedance measurements have also shown the evidence of grain boundary conduction and lowering of barrier to the motion of charge carriers with rise in temperature. Using the Arrhenius plot of dc conductivity, the corresponding activation energy for both grain and grain boundary were 0.32 eV and 0.38 eV, respectively. The values revealed that the composite ceramic was attributed to the motion of oxygen vacancies within the bulk. We also found that the relaxation frequency shift to high side with increase in temperature. In addition, the sample exhibits hysteresis loop typical of magnetic behavior. The saturation magnetization increases from 2.38 to 3.13 emu/g and the coercivity increases from 0.2 to 0.7 Oe with increasing temperature.
Nickel ferrite NiFe2O4 (NFO) thin films have been prepared on Si substrate (NFO/Si) and on La0.7Sr0.3MnO3 (LSMO)-coated Si (100) substrate (NFO/LSMO/Si) by RF magnetron sputtering. The microstructures and magnetic properties of the two films were systematically investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) revealed that the high (331)-oriented NFO films were grown on LSMO/Si substrate with smooth surface and cross-section morphologies. The samples show a clear hysteresis loop with in-plane H the magnetization. However, both samples do not show any hysteresis with the magnetic field applied perpendicular to the films plane, which indicates the presence of an anisotropy favoring the orientation of the magnetization in the direction parallel to the films plane. Study of magnetization hysteresis loop measurements reflects that LSMO buffer layer may improve the magnetic properties of NFO thin films, and the saturation magnetization increases from 41.5 to 350 emu/cm3.
We also explored the influence of different growth atmosphere to the structure and properties of NFO films. NFO thin films on Si (100) substrate have been prepared by RF magnetron sputtering. The growth atmosphere consisted either of pure Ar or of a Ar/O2 mixture. The results show that both of the films deposited by two kinds of atmospheres exhibit spinel structure, and the preferential orientation changes when adding some oxygen. In addition, it is found that the magnetic properties of the deposited NFO films with oxygen are significantly improved(MS=41.5 emu/cm3).
本文首先采用传统高温固相反应法成功制备了0.45NFO-0.55BTO复合陶瓷。利用复阻抗方法,测试频率从20Hz到2MHz,测试温度为348K至473K,系统地研究了样品的电性能,通过Cole-Cole图,计算了样品的晶粒、晶界电阻值和弛豫时间常数。结果表明,样品的自由电子浓度随温度升高而增加。利用直流电导率的Arrhenius曲线计算了晶粒和晶界的电导率激活能分别为0.32eV和0.38eV,存在这一激活能数值的主要原因是样品中氧空位的迁移,我们也发现弛豫特征频率随着温度升高而升高。另外,样品呈现了典型的磁化曲线,随着测试温度升高,饱和磁化强度(Ms)从2.38emu/g增加到3.13emu/g,矫顽力由0.20e增加到0.70e。
然后我们采用射频磁控溅射法在Si(100)基片上分别制备了NFO薄膜(NFO/Si)和NiFe2O4/La0.7Sr0.3MnO3异质结(NFO/LSMO/Si),研究了LSMO缓冲层对NFO薄膜结构及磁性能的影响。经XRD和扫描电镜(SEM)测试,发现LSMO缓冲层有利于NFO薄膜沿(331)方向择优生长,制备的NFO薄膜的表面是很平整和均匀的。经磁性测试,当薄膜表面与磁场平行时,发现样品在室温下呈现出饱和的磁滞回线,当薄膜表面与磁场垂直时,没有发现任何磁化现象,这表明NFO薄膜平行于磁化方向时存在各向异性。从样品磁滞回线中可以看出,LSMO缓冲层有利于提高NFO薄膜的磁性能,其Ms由41.5 emu/cm3增加到350emu/cm3。
我们也研究了溅射气氛对NFO薄膜结构与磁性能的影响。利用射频磁控溅射法在Si(100)基片上制备了NFO薄膜,溅射气氛包括纯Ar和Ar/O2混合气体。结果表明,在两种不同气氛中沉积的薄膜样品都呈立方尖晶石结构,通入少量氧气之后,薄膜择优取向发生改变,并且磁性能得到改善(Ms为41.5emu/cm3)。
Ferrite materials are widely used in electronics, information, machinery and other industrial areas. Ferrite is a magnetic material has a unique high resistivity and good high frequency characteristics. Those properties have attracted considerable interest in recent years since they might offer the potential to enhance the performance or shrink the dimensional sizes of the microelectronic devices. At present, the ferrite materials are becoming an important research field of the magnetic materials. In the present work, NiFe2O4 (NFO) is one of the most versatile and technologically important ferrite materials. BaTiO3 (BTO) material is a typical ferroelectric material, so it has great application prospect in the electric tuning microwave components.
The standard double sintering ceramic method was used to prepare the 0.45NFO-0.55BTO composite ceramic. Complex impedance spectroscopy of 0.45NFO-0.55BTO composite ceramic on the electrical characteristics were studied. The grain resistance, grain boundary resistance and relaxation time constant were calculated from the Cole-Cole plot. Impedance spectroscopy measurements were conducted in a frequency range from 20 Hz to 2 MHz and in a temperature range from 348 to 473 K. The impedance measurements have also shown the evidence of grain boundary conduction and lowering of barrier to the motion of charge carriers with rise in temperature. Using the Arrhenius plot of dc conductivity, the corresponding activation energy for both grain and grain boundary were 0.32 eV and 0.38 eV, respectively. The values revealed that the composite ceramic was attributed to the motion of oxygen vacancies within the bulk. We also found that the relaxation frequency shift to high side with increase in temperature. In addition, the sample exhibits hysteresis loop typical of magnetic behavior. The saturation magnetization increases from 2.38 to 3.13 emu/g and the coercivity increases from 0.2 to 0.7 Oe with increasing temperature.
Nickel ferrite NiFe2O4 (NFO) thin films have been prepared on Si substrate (NFO/Si) and on La0.7Sr0.3MnO3 (LSMO)-coated Si (100) substrate (NFO/LSMO/Si) by RF magnetron sputtering. The microstructures and magnetic properties of the two films were systematically investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) revealed that the high (331)-oriented NFO films were grown on LSMO/Si substrate with smooth surface and cross-section morphologies. The samples show a clear hysteresis loop with in-plane H the magnetization. However, both samples do not show any hysteresis with the magnetic field applied perpendicular to the films plane, which indicates the presence of an anisotropy favoring the orientation of the magnetization in the direction parallel to the films plane. Study of magnetization hysteresis loop measurements reflects that LSMO buffer layer may improve the magnetic properties of NFO thin films, and the saturation magnetization increases from 41.5 to 350 emu/cm3.
We also explored the influence of different growth atmosphere to the structure and properties of NFO films. NFO thin films on Si (100) substrate have been prepared by RF magnetron sputtering. The growth atmosphere consisted either of pure Ar or of a Ar/O2 mixture. The results show that both of the films deposited by two kinds of atmospheres exhibit spinel structure, and the preferential orientation changes when adding some oxygen. In addition, it is found that the magnetic properties of the deposited NFO films with oxygen are significantly improved(MS=41.5 emu/cm3).
引文
[1]贡长生,张克力.新型功能材料[M].北京：化学工业出版社,2001
[2]李云凯,周张健.陶瓷及其复合材料[M].北京：北京理工大学出版社,2007
[3]熊兆贤.材料物理导论[M].北京：科学出版社,2000
[4]William D, Callister J. Materials Science and Engineering [M]. An Introduction. USA, John Wiley & Sons,1999
[5]都有为.铁氧体[M].江苏：江苏科学技术出版社,1996
[6]孙康宁,尹衍升,李爱民.金属间化合物／陶瓷基复合材料[M].北京：机械工业出版社,2003
[7]Pask J A. In:Yen T S, Pask J A.,(ed). Microstracture and properties of ceramic materials [Z]. Beijing:Science Press,1984
[8]Buessem W R, Cross L E, Goswami A K. Phenomenological theory of high permittivity in fine-grained barium titanate [J]. J. Amer. Ceram. Soc.1966,49(1):33-36
[9]Metoseriu L, Tura V, Papusoi C, Osaka T, Okuyama M. A comparative study of the grain size effects on ferro-para phase transition in barium titanate ceramics [J]. Ferroelectrics,1999,223:99-106
[10]Arlt G, Hennings D, G de with. Dielectric properties of fine-grained barium titanate ceramics [J]. J. Appl. Phys.1985,58(4):1619-1625
[11]Y. Oishi and W.D. Kingery. Self-Diffusion of Oxygen in Single Crystal and Polycrystalline Aluminum Oxide [J]. J. Chem. Phys.1960,33(2):480
[12]殷庆瑞,祝炳和.功能陶瓷的显微结构、性能与制备技术[M].北京：冶金工业出版社,2005
[13]徐祖耀,李朋兴.材料科学导论[M].上海：上海科学出版社,1986
[14]关振铎,张中太,焦金生.无机材料物理性能[M].北京：清华大学出版社,1994
[15]李言荣,恽正中.材料物理学概论[M],北京：清华大学出版社,2001
[16]田莳.材料物理性能[M].北京：北京航空航天大学出版社,2001
[17]王国梅,万发荣.材料物理[M].武汉：武汉理工大学出版社,2004
[18]陈树川,陈棱冰.材料物理性能[M],上海：上海交通大学出版社,1999
[19]S. Ananta and N.W. Thomas. Relatiinships between Sintering Conditions, Microstructure and Dielectric Properties of Lead Iron Niobate [J]. J Eur Cer Soc,1999,19: 1873-1881
[20]K. Singh, S.A. Band, W.K. King. Effect of Sintering Temperature on Dielectric Properties of Pb(Fe1/2Nb1/2)O3 Perovskite Material [J]. Ferroelectrics,2004,306:179-185
[21]D.R. Patil, S.A.Lokare, S.S. Chougule, B.K. Chougule. Dielectric and magnetic properties of xNiFe204+(1-x)Ba0.9Sr0.1TiO3 composites [J]. Phys. B,2007,400:77-82
[22]K.K. Patankar, P.D. Dombale, V.L. Mathe, S.A. Patil, R.N. Patil. AC conductivity and magnetoelectric effect in MnFe1.8Cr0.2O4-BaTiO3 composites [J]. Mater. Sci. Eng. B, 2001,87:53-58
[23]E.V. Ramana, S.V. Suryanarayana, T.B. Sankaram. Ac impedance studies on ferroelectromagnetic SrBi5-xLaxTi4FeO18 ceramics [J]. Mater. Res. Bull,2006,41:1077-1088
[24]P. Dhak, D. Dhak, M. Das, K. Pramanik, P. Pramanik. Impedance spectroscopy study of LaMnO3 modified BaTiO3 ceramics [J]. Mater. Sci. Eng. B,2009,164:165-171
[25]R. Souza, J. Fleig, J. Maier, et al. Electrical resistance of low-angle tilt grain boundaries in acceptor-doped SrTiO3 as a function of misorientation angle [J]. J. Appl. Phys, 2005,97:053502
[26]C. Elissalde and J. Ravez. Ferroelectric ceramics:defects and dielectric relaxations [J]. J. Mater. Chem,2001,11:1957-1967
[27]G. Singh and V.S. Tiwari. Effect of Zr concentration on conductivity behavior of (1-x)PMN-xPZ ceramic:An impedance spectroscopy analysis [J]. J. Appl. Phys.2009,106: 124104
[28]C. Ang, Z. Yu, L.E. Cross. Oxygen-vacancy-related low-frequency dielectric relaxation and electrical conduction in Bi:SrTiO3 [J]. Phys. Rev. B,2000,62:228-236
[29]S.H. Yoon, C.A. Randall, K.H. Hur. Influence of Grain Size on Impedance Spectra and Resistance Degradation Behavior in Acceptor (Mg)-Doped BaTiO3 Ceramics [J]. J. Am. Ceram. Soc,2009,92(12):2944-2952
[30]E. Atamanik, V. Thangadurai. Dielectric Properties of Ga-Doped [J]. J. Phys. Chem. C,2009,113:4648-4653
[31]J.D. Bobic, M.M. Vijatovic, S. Greicius, J. Banys, B.D. Stojanovic. Dielectric and relaxor behavior of BaBi4Ti4O15 ceramics [J]. J. Alloys. Compd,2010,499:221-226
[32]S.K. Rout, A. Hussian, J.S. Lee, I.W. Kim, S.I. Woo. Impedance spectroscopy and morphology of SrBi4Ti4O15 ceramics prepared by soft chemical method [J]. J. Alloys. Compd,2009,477:706-711
[33]A. Singh, V. Pandey, R.K. Kotnala, D. Pandey. Direct Evidence for Multiferroic Magnetoelectric Coupling in 0.9BiFeO3-0.1BaTiO3 [J]. Phys. Rev. B,2008,101:247602
[34]P. Vavassori, E. Angeli, D. Bisero, F. Spizzo, F. Ronconi. Role of particle size distribution on the temperature dependence of coercive field in sputtered Co/Cu granular films [J]. Appl. Phys. Lett,2001,79(14):2225
[35]周小莉.沉积在液体基底表面铁薄膜的矫顽力与温度关系研究[J].真空科学与技术学报,2007,28(2)：116-119
[36]周小莉,魏纳新.颗粒大小分布对铁薄膜矫顽力的影响研究[J].物理学进展,2006,26：511-515
[37]戴道生、钱昆明,铁磁学[M],科学出版社,1987
[38]J.L Gunjakar, A.M. More, V.R. Shinde, C.D. Lokhande. Synthesis of nanocrystalline nickel ferrite (NiFe2O4) thin films using low temperature modified chemical method [J]. J. Alloys. Compd,2008,465:468-473
[39]N.A. Spaldin, W.E. Pickett. Computational design of multifunctional materials [J]. J. Solid State Chem,2003,176:615-632
[40]赵义恒,张药西.软磁材料的技术进展及选择[J].电子元器件应用.2009,11(3)：73
[41]高银浩,张文庆.纳米磁性材料的制备及应用的新进展[J].广州化工.2009,37(5)：6-8
[42]M. Srivastava, A.K. Ojha, S. Chaubey, A. Materny. Synthesis and optical characterization of nanocrystalline NiFe2O4 structures [J]. J. Alloys. Compd,2009,481: 515-519
[43]M.T. Johnson, P.G. Kotula, C.B. Carter. Growth of nickel ferrite thin films using pulsed-laser deposition [J]. J. Cryst Growth,1999,206:299-307
[44]J. Gao, Y. Cui, Z. Yang. The magnetic properties of NixZn1-xFe2O4 films fabricated by alternative sputtering technology [J]. Mater. Sci. Eng. B,2004,110:111-114
[45]于永杰,杨成韬,王磊,陈强,张亚磊.射频溅射法制备的CoFe2O4薄膜结构及磁性能[J].磁性材料及器件,2009,40(6)：19
[46]孙科,兰中文,聂小亮,余忠,赵晓宁,李乐中.退火温度对NiZn铁氧体薄膜性能的影响[J].2009,31(5)：709-711
[47]F. Rigato, S. Estrade, J. Arbiol, et al. Strain-induced stabilization of new magnetic spinel structures in epitaxial oxide heterostructures [J]. Mater. Sci. Eng. B,2007, 144:43-48.
[48]王丽丽,王欣,宫杰,郑伟涛,宗占国.衬底温度对Fe-N薄膜结构、形貌及磁性能的影响[J].中国有色金属学报,2005,15(11)：1838-1842.
[49]A. Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido, Y. Tokura. Insulator-metal transition and giant magnetoresistance in La1-xSrxMnO3 [J]. Phys. Rev. B, 1995,51(20):14103-14109
[50]Z.J. Wang, H. Usuki, T. Kumagai, H. Kokawa. Microstructure and electrical properties of La0.7Sr0.3MnO3 thin films deposited by metallo-organic decomposition method [J]. J. Cryst. Growth,2006,293:68-73
[51]C.N. Chinnasamy, A. Narayanasamy, N. Ponpandian, et al. Mixed spinel structure in nanocrystalline NiFe2O4 [J]. Phys. Rev. B,2001,63:184108
[52]A. Huignard, A. Aron, P. Aschehoug, B. Viana, et al. Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical application [J]. J. Mater. Chem,2000,10:549-554
[53]潘金生,全健民,田民波.材料科学基础[M].北京：清华大学出版社.2004
[54]Y. Wu, J. Wan, C. Huang, Y. Weng, et al. Strong magnetoelectric coupling in multiferroic BiFe03-Pb(Zr0.52Ti0.48)O3 composite films derived from electrophoretic deposition [J].2008,93:192915
[55]W. Eerenstein, et al. Comment on "Epitaxial BiFeO3 Multiferroic Thin Film Heterostructures" [J]. Science,2005,307:1203a
[56]U. Luders, A. Barthelemy, M. Bibes, K. Bouzehouane. S. Fusil, E. Jacquet, J. Contour, J. Bobo, J. Fontcuberta, and A. Fert. NiFe2O4:A Versatile Spinel Material Brings New Opportunities for Spintronics [J]. Adv. Mater.2006,18:1733-1736
[57]C.R. Brundle, T.J. Chuang, K. Wandelt. Core and valence level photoemission studies of iron oxide surfaces and the oxidation of iron [J]. Surf. Sci,1977,68:459-468
[58]X.W. Xi, Y.J. Chen, X.Y. Zhang. Growth and magnetic properties of soft ferrite films by pulsed laser deposition [J]. Vacuum,2004,75:161-167
[59]廖国进,骆红,闫绍峰,朱振华.氧分压对Al2O3:Ce薄膜的发光性能及表面形貌的影响[J].功能材料与器件,2010,16(2)：119-124
[2]李云凯,周张健.陶瓷及其复合材料[M].北京：北京理工大学出版社,2007
[3]熊兆贤.材料物理导论[M].北京：科学出版社,2000
[4]William D, Callister J. Materials Science and Engineering [M]. An Introduction. USA, John Wiley & Sons,1999
[5]都有为.铁氧体[M].江苏：江苏科学技术出版社,1996
[6]孙康宁,尹衍升,李爱民.金属间化合物／陶瓷基复合材料[M].北京：机械工业出版社,2003
[7]Pask J A. In:Yen T S, Pask J A.,(ed). Microstracture and properties of ceramic materials [Z]. Beijing:Science Press,1984
[8]Buessem W R, Cross L E, Goswami A K. Phenomenological theory of high permittivity in fine-grained barium titanate [J]. J. Amer. Ceram. Soc.1966,49(1):33-36
[9]Metoseriu L, Tura V, Papusoi C, Osaka T, Okuyama M. A comparative study of the grain size effects on ferro-para phase transition in barium titanate ceramics [J]. Ferroelectrics,1999,223:99-106
[10]Arlt G, Hennings D, G de with. Dielectric properties of fine-grained barium titanate ceramics [J]. J. Appl. Phys.1985,58(4):1619-1625
[11]Y. Oishi and W.D. Kingery. Self-Diffusion of Oxygen in Single Crystal and Polycrystalline Aluminum Oxide [J]. J. Chem. Phys.1960,33(2):480
[12]殷庆瑞,祝炳和.功能陶瓷的显微结构、性能与制备技术[M].北京：冶金工业出版社,2005
[13]徐祖耀,李朋兴.材料科学导论[M].上海：上海科学出版社,1986
[14]关振铎,张中太,焦金生.无机材料物理性能[M].北京：清华大学出版社,1994
[15]李言荣,恽正中.材料物理学概论[M],北京：清华大学出版社,2001
[16]田莳.材料物理性能[M].北京：北京航空航天大学出版社,2001
[17]王国梅,万发荣.材料物理[M].武汉：武汉理工大学出版社,2004
[18]陈树川,陈棱冰.材料物理性能[M],上海：上海交通大学出版社,1999
[19]S. Ananta and N.W. Thomas. Relatiinships between Sintering Conditions, Microstructure and Dielectric Properties of Lead Iron Niobate [J]. J Eur Cer Soc,1999,19: 1873-1881
[20]K. Singh, S.A. Band, W.K. King. Effect of Sintering Temperature on Dielectric Properties of Pb(Fe1/2Nb1/2)O3 Perovskite Material [J]. Ferroelectrics,2004,306:179-185
[21]D.R. Patil, S.A.Lokare, S.S. Chougule, B.K. Chougule. Dielectric and magnetic properties of xNiFe204+(1-x)Ba0.9Sr0.1TiO3 composites [J]. Phys. B,2007,400:77-82
[22]K.K. Patankar, P.D. Dombale, V.L. Mathe, S.A. Patil, R.N. Patil. AC conductivity and magnetoelectric effect in MnFe1.8Cr0.2O4-BaTiO3 composites [J]. Mater. Sci. Eng. B, 2001,87:53-58
[23]E.V. Ramana, S.V. Suryanarayana, T.B. Sankaram. Ac impedance studies on ferroelectromagnetic SrBi5-xLaxTi4FeO18 ceramics [J]. Mater. Res. Bull,2006,41:1077-1088
[24]P. Dhak, D. Dhak, M. Das, K. Pramanik, P. Pramanik. Impedance spectroscopy study of LaMnO3 modified BaTiO3 ceramics [J]. Mater. Sci. Eng. B,2009,164:165-171
[25]R. Souza, J. Fleig, J. Maier, et al. Electrical resistance of low-angle tilt grain boundaries in acceptor-doped SrTiO3 as a function of misorientation angle [J]. J. Appl. Phys, 2005,97:053502
[26]C. Elissalde and J. Ravez. Ferroelectric ceramics:defects and dielectric relaxations [J]. J. Mater. Chem,2001,11:1957-1967
[27]G. Singh and V.S. Tiwari. Effect of Zr concentration on conductivity behavior of (1-x)PMN-xPZ ceramic:An impedance spectroscopy analysis [J]. J. Appl. Phys.2009,106: 124104
[28]C. Ang, Z. Yu, L.E. Cross. Oxygen-vacancy-related low-frequency dielectric relaxation and electrical conduction in Bi:SrTiO3 [J]. Phys. Rev. B,2000,62:228-236
[29]S.H. Yoon, C.A. Randall, K.H. Hur. Influence of Grain Size on Impedance Spectra and Resistance Degradation Behavior in Acceptor (Mg)-Doped BaTiO3 Ceramics [J]. J. Am. Ceram. Soc,2009,92(12):2944-2952
[30]E. Atamanik, V. Thangadurai. Dielectric Properties of Ga-Doped [J]. J. Phys. Chem. C,2009,113:4648-4653
[31]J.D. Bobic, M.M. Vijatovic, S. Greicius, J. Banys, B.D. Stojanovic. Dielectric and relaxor behavior of BaBi4Ti4O15 ceramics [J]. J. Alloys. Compd,2010,499:221-226
[32]S.K. Rout, A. Hussian, J.S. Lee, I.W. Kim, S.I. Woo. Impedance spectroscopy and morphology of SrBi4Ti4O15 ceramics prepared by soft chemical method [J]. J. Alloys. Compd,2009,477:706-711
[33]A. Singh, V. Pandey, R.K. Kotnala, D. Pandey. Direct Evidence for Multiferroic Magnetoelectric Coupling in 0.9BiFeO3-0.1BaTiO3 [J]. Phys. Rev. B,2008,101:247602
[34]P. Vavassori, E. Angeli, D. Bisero, F. Spizzo, F. Ronconi. Role of particle size distribution on the temperature dependence of coercive field in sputtered Co/Cu granular films [J]. Appl. Phys. Lett,2001,79(14):2225
[35]周小莉.沉积在液体基底表面铁薄膜的矫顽力与温度关系研究[J].真空科学与技术学报,2007,28(2)：116-119
[36]周小莉,魏纳新.颗粒大小分布对铁薄膜矫顽力的影响研究[J].物理学进展,2006,26：511-515
[37]戴道生、钱昆明,铁磁学[M],科学出版社,1987
[38]J.L Gunjakar, A.M. More, V.R. Shinde, C.D. Lokhande. Synthesis of nanocrystalline nickel ferrite (NiFe2O4) thin films using low temperature modified chemical method [J]. J. Alloys. Compd,2008,465:468-473
[39]N.A. Spaldin, W.E. Pickett. Computational design of multifunctional materials [J]. J. Solid State Chem,2003,176:615-632
[40]赵义恒,张药西.软磁材料的技术进展及选择[J].电子元器件应用.2009,11(3)：73
[41]高银浩,张文庆.纳米磁性材料的制备及应用的新进展[J].广州化工.2009,37(5)：6-8
[42]M. Srivastava, A.K. Ojha, S. Chaubey, A. Materny. Synthesis and optical characterization of nanocrystalline NiFe2O4 structures [J]. J. Alloys. Compd,2009,481: 515-519
[43]M.T. Johnson, P.G. Kotula, C.B. Carter. Growth of nickel ferrite thin films using pulsed-laser deposition [J]. J. Cryst Growth,1999,206:299-307
[44]J. Gao, Y. Cui, Z. Yang. The magnetic properties of NixZn1-xFe2O4 films fabricated by alternative sputtering technology [J]. Mater. Sci. Eng. B,2004,110:111-114
[45]于永杰,杨成韬,王磊,陈强,张亚磊.射频溅射法制备的CoFe2O4薄膜结构及磁性能[J].磁性材料及器件,2009,40(6)：19
[46]孙科,兰中文,聂小亮,余忠,赵晓宁,李乐中.退火温度对NiZn铁氧体薄膜性能的影响[J].2009,31(5)：709-711
[47]F. Rigato, S. Estrade, J. Arbiol, et al. Strain-induced stabilization of new magnetic spinel structures in epitaxial oxide heterostructures [J]. Mater. Sci. Eng. B,2007, 144:43-48.
[48]王丽丽,王欣,宫杰,郑伟涛,宗占国.衬底温度对Fe-N薄膜结构、形貌及磁性能的影响[J].中国有色金属学报,2005,15(11)：1838-1842.
[49]A. Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido, Y. Tokura. Insulator-metal transition and giant magnetoresistance in La1-xSrxMnO3 [J]. Phys. Rev. B, 1995,51(20):14103-14109
[50]Z.J. Wang, H. Usuki, T. Kumagai, H. Kokawa. Microstructure and electrical properties of La0.7Sr0.3MnO3 thin films deposited by metallo-organic decomposition method [J]. J. Cryst. Growth,2006,293:68-73
[51]C.N. Chinnasamy, A. Narayanasamy, N. Ponpandian, et al. Mixed spinel structure in nanocrystalline NiFe2O4 [J]. Phys. Rev. B,2001,63:184108
[52]A. Huignard, A. Aron, P. Aschehoug, B. Viana, et al. Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical application [J]. J. Mater. Chem,2000,10:549-554
[53]潘金生,全健民,田民波.材料科学基础[M].北京：清华大学出版社.2004
[54]Y. Wu, J. Wan, C. Huang, Y. Weng, et al. Strong magnetoelectric coupling in multiferroic BiFe03-Pb(Zr0.52Ti0.48)O3 composite films derived from electrophoretic deposition [J].2008,93:192915
[55]W. Eerenstein, et al. Comment on "Epitaxial BiFeO3 Multiferroic Thin Film Heterostructures" [J]. Science,2005,307:1203a
[56]U. Luders, A. Barthelemy, M. Bibes, K. Bouzehouane. S. Fusil, E. Jacquet, J. Contour, J. Bobo, J. Fontcuberta, and A. Fert. NiFe2O4:A Versatile Spinel Material Brings New Opportunities for Spintronics [J]. Adv. Mater.2006,18:1733-1736
[57]C.R. Brundle, T.J. Chuang, K. Wandelt. Core and valence level photoemission studies of iron oxide surfaces and the oxidation of iron [J]. Surf. Sci,1977,68:459-468
[58]X.W. Xi, Y.J. Chen, X.Y. Zhang. Growth and magnetic properties of soft ferrite films by pulsed laser deposition [J]. Vacuum,2004,75:161-167
[59]廖国进,骆红,闫绍峰,朱振华.氧分压对Al2O3:Ce薄膜的发光性能及表面形貌的影响[J].功能材料与器件,2010,16(2)：119-124