TiO_2/SnO_2基稀磁半导体及铁氧体基复合材料磁性和交换偏置效应
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摘要
稀稀稀稀稀(DMS)和受限稀系统中稀耦基和和的研究是当前自旋电子学领域的前沿课题。其中,对铁材材稀稀稀稀稀以及新型铁材材受限稀系统的稀磁和和和和和和和的研究显得尤为重要,它将为研制新一代自旋电子器件奠定材材基础。本博选择过渡金属(Mn,V)掺杂的TiO_2/SnO_2稀稀稀稀稀和铁铁稀嵌入反铁稀NiO的颗粒系统作为研究对象,探讨了样品的微观结构和稀磁质之间的关系。具稀工作包括以下几个方面:
     1.采用固相反和法制备了Mn掺杂的TiO_2块材样品,对样品的掺杂组分、烧结温度和烧结气氛对稀磁的影响进行了研究。对Ti_(1-x)Mn_xO_2(x=0.02)块材样品,比较了氩气和空气中烧结的样品的稀材行为,实验表田烧结气氛和烧结温度是两个非常重要的因素。对氩气中烧结的样品,当烧结温度较低时,室温铁稀磁最大,随退火温度的升高,铁稀磁单调递减。而空气中烧结的样品,随烧结温度的增加,铁稀磁先增加然后减小。对Ts=600oC烧结处材的样品,稀材研究表田,对空气中烧结的样品,稀材率曲线符基居里-外斯定律,在整个温区都没观察的稀转变:对氩气中烧结的样品,室温附近观察到了稀转变。对样品室温铁稀磁的起因,我们运用束缚稀极材子材博进行了解释,认为界面层的Mn离子掺杂和铁空博缺陷的存在是诱稀铁稀磁出现的两个关键因素。
     2.对Mn掺杂TiO_2样品的稀和和和和和和进行了研究。其中,对Ts=450oC烧结的Ti_(1-x)Mn_xO_2(x=0.04)样品,当外加1T稀场将样品冷却到50K以下时,样品可同时观察到水平和垂直和和和和和和,和和和和和和起因于铁稀磁的Ti_(1-x)Mn_xO_2和反铁稀磁的Mn_2O_3和(Ti_(1-x)Mn_xO)Mn_2O_4等锰铁材材界面的稀耦基。对Ts=600oC氩气烧结的Ti_(1-x)Mn_xO_2(x=0.04)块材样品,当温度低于60K时,样品表现出水平的和和和和场和和,实验观察到的和和和和和和起因于Ti_(1-x)Mn_xO_2/Mn_2O_3和Mn_3O_4/Mn_2O_3两种界面和和和和和和的叠加行为。以上和和和和和和的出现为Ti_(1-x)Mn_xO_2的铁稀行为提供了又一证据。
     3.采用sol-gel法制备的Ti_(1-x)V_xO_2 (0≦x≦0.16)纳米粉,探讨了退火工艺对样品的微观结构和稀磁的影响。XRD和Raman光谱分析表田,钒离子可以进入TiO_2的晶格,形成了本征的稀稀结构,并且随退火温度的增加,样品从锐钛矿相逐渐向金红石相过渡。稀磁测量表田,空气中预处材的样品,观察到了铁稀和抗稀的并存行为;在氩气中退火处材后,样品的铁稀磁逐渐增强,并且随退火温度的增加,铁稀磁逐渐增强。运用束缚稀极材子材博对以上实验现象进行了解释,认为氩气中退火晶界缺陷的增加是稀致铁稀磁增强的主要原因。
     4.采用材学共沉淀法成功的基成了Sn_(1-x)Mn_xO_2 (0.01≦x≦0.07)纳米粉,对样品掺杂浓度和退火温度对稀磁的影响进行了研究。实验表田,低的掺杂浓度和低温热处材有利于铁稀磁的形成。当退火温度Ts=450oC,发现掺杂浓度x≦0.05时,样品在室温下表现出田显的铁稀磁;掺杂浓度x≥0.07时,样品完全转变为顺稀行为。对Sn_(0.97)Mn_(0.03)O_2样品,随退火温度的升高,铁稀磁减弱,当退火温度Ts=800oC时,铁稀磁基本消失。
     5.采用材学共沉淀法并结基高温相和析原材制备了NiFe_2O_4纳米颗粒嵌入反铁稀NiO母稀的颗粒系统,对这一受限稀系统的和和和和和和进行了研究,探讨了样品的微结构和稀和和和和和和之间的关系。对Ts=600oC退火处材的样品,发现了垂直和水平和和和和和和,当温度T=10K时,和和和和场HEB≈3050 Oe,垂直的稀材强度平移量△M/MS≈10%。对Ts=750oC退火处材的样品,只发现了水平和和和和和和,当温度T=10K时,对和的和和和和场HEB≈260 Oe。
The magnetic coupling properties in diluted magnetic semiconductors (DMS) and limited magnetic systems are one of the foreland fields of spintronics. In which, the study on magnetism and exchange bias effect in oxide-based DMSs and oxide-related composites becomes particularly important, because it lay the foundations of developing practical applications of spintronic devices. In this thesis, our studies focus on the transition metal (Mn, V) doped TiO_2/SnO_2 diluted magnetic semiconductors samples and a granular system of ferrite embedded an antiferromagnetic NiO matrix. The relationship between the microstructure and the magnetic properties is established. The main contents of this thesis can be summarized as follows:
     1. The Mn-doped TiO_2 polycrystalline bulk samples were synthesized by standard solid state reaction method, and then effects of doping content, sintering temperature and atmosphere on the magnetism have been studied. As for the Ti_(1-x)Mn_xO_2 (x=0.02) samples, the results show that the magnetic properties are strongly dependent on the sintering temperature and atmosphere. For samples sintered in air, the magnetization initially increase with the increase of sintering temperature up to 600oC and thereafter it decrease. While the magnetization of samples sintered in argon atmosphere decreases monotonically with the increase of sintering temperature. Furthermore, for samples sintered at 600oC in air, the magnetic susceptibility exhibits a dominant Curie-Weiss behavior and no magnetic transition is observed over the temperature range from 10K to 300K. In contrast, for samples sintered in argon atmosphere, besides the magnetic transition near 45 K perhaps caused by Mn3O4, another magnetic transition appears near room temperature. Additionally, in the framework of bound magnetic polaron theory, it shows that the existence of large number of oxygen vacancies and magnetic ions at the grain boundaries of Ti_(1-x)Mn_xO_2 particles play critical roles in activation of the ferromagnetism.
     2. The exchange bias effect in Mn doped TiO_2 bulk samples have been studied. For the Ti_(1-x)Mn_xO_2(x=0.04) samples sintered at 450oC, both horizontal and vertical exchange bias effect is observed when the samples were cooled below 50K under 1T. The observed exchange bias effect can be interpreted considering that the magnetic coupling between ferromagnetic Ti_(1-x)Mn_xO_2 and antiferromagnetic Mn_2O_3 (Ti_(1-x)Mn_xO)Mn_2O_4. For the Ti_(1-x)Mn_xO_2(x=0.04) samples sintered at 600oC, horizontal exchange bias effect is clearly observed after field cooled below 60 K, which is attributed to the exchange coupling between antiferromagnetic Mn_2O_3 with ferrimagnetic Mn3O4 and ferromagnetic Ti_(1-x)Mn_xO_2. This exchange bias behavior also provides strong support for the RTFM in Ti_(1-x)Mn_xO_2.
     3. Polycrystalline nanoparticles with nominal composition Ti_(1-x)V_xO_2 (0≦x≦0.16) were synthesized by a sol-gel technique in air, and then the samples were postannealed in argon atmosphere at different temperatures from 500oC to 850oC. The XRD and Raman spectroscopy analysis show that the Vanadium ions can be incorporated into the TiO_2 lattice. Furthermore, the microstructure shows that the samples transform from anatase phase to rutile phase of TiO_2 as the annealing temperature increases to 700oC. Meanwhile, room temperature ferromagnetism is enhanced after postannealing in argon atmosphere and the ferromagnetism increases with annealing temperatures. A plausible explanation for the enhancement of ferromagnetism with annealing temperatures is presented in terms of bound magnetic polaron model.
     4. The Mn-doped SnO_2 nanoparticles were synthesized by chemical co-precipitation method, the effect of doping contents and annealing temperature on the magnetism has been investigated. The results show that both a correct doping content and appropriate sintering temperature are crucial for the activation of room temperature ferromagnetism. No ferromagnetism is observed for samples sintered at 800oC, irrespective of the doping content. In contrast, the samples sintered at low temperature (Ts=450oC) can exhibit room temperature ferromagnetism when the doping content is below 0.05. Furthermore, the ferromagnetism decreases with the increase of annealing temperature. The results indicate that the ferromagnetism in Sn_(1-x)Mn_xO_2 nanoparticles is highly correlated to the surface structural defects.
     5. A granular system composed of ferrimagnetic (Ferri) NiFe_2O_4 nanoparticles embedded in an antiferromagnetic (AFM) NiO matrix has been synthesized by a high-temperature phase precipitation method from Fe-doped NiO matrix. Magnetic studies show that, exchange bias effect can be observed below 250 K in this system. For the samples annealed at 600oC, exchange bias field (HEB) can be as large as 3050 Oe and the enhanced coercivity (△HC) reach 2150 Oe at 10 K. In addition, the accompanied magnetization shift can be reached 10%. This exchange bias effect can be explained in terms of the existence of frozen spins at the Ferri/AFM interface. For the samples annealed at 750oC, only horizontal exchange bias effect is observed, the corresponding exchange bias field (HEB) is about 260 Oe at 10K.
引文
[1] Baibich M N, Broto J M, Fert A, et al. Giant magnetoresistance of (001) Fe/(001) Cr magnetic superlattices. Phys. Rev. lett., 1988, 61 (21): 2472-2475.
    [2] Dietl, H. Ohno, F. Matsukura, J et al. Zenar model description of ferromagnetism in zinc-blende magnetic semiconductors. Science, 2000, 287:1019-1022
    [3] Matsumoto Y, Murakami M, Shono T et al. Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide. Science, 2001, 291: 854-856
    [4] Skumryev V, Stoyanov S, Zhang Y, et al. Beating the superparamagnetic limit with exchange bias, Nature, 2003, 423: 850-853
    [5] De Boeck, Van Roy W, Das J, et al. Technology and materials issues in semiconductor-based magnetoelectronics. Semicond Sci & Tech, 2002, 17(4): 342-354
    [6] Dietl T. Spintronics and ferromagentism in wide-band-gap semiconductors. AIP conf Proc, 2005, 56: 772
    [7] Vouille C, Barthelemy A, Mpondo F E, Fert A, et al. Microscopic mechanisms of giant magnetoresistance. Phys. Rev B, 1999, 60: 006710
    [8] Borchers J A, Gehring P M, Erwin R W, et al. Antiferromagnetic interlayer correlation in annealed Ni80Fe20/Ag multilayers. Phys. Rev B, 1996, 54: 009870
    [9] Kubota H, Sato M, Miyazaki T. Temperature dependence of giant magnetoresistance in Ni-Co/Cu, Ni-Fe/Cu, and Co-Fe/Cu multilayer films. Phys. Rev B, 1995, 52: 000343
    [10] White R L. Giant magnetoresistance: a primer. IEEE Transactions on magnetics.1992, 28 (5): 2482-2487.
    [11] Julliere M. Tunneling between ferromagnetic films. Phys. Lett. A, 1975, 54 (3): 225-226.
    [12] Miyazaki T, Tezuka N. Spin polarized tunneling in ferromagnet/insulator/ferromagnet junctions. J. Magn. Magn. Mater, 1995, 151 (3) : 403-410.
    [13] Moodera J S, Lisa R. Kinder, et al. Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions. Phys. Rev. Lett, 1995, 74 (16): 3273-3276.
    [14] Zutic I, Fabian J, Sarma S D. Spintronics: fundamentals and applications. Rev. Mod. Phys, 2004, 76:323-386
    [15] Biber M, Barthelemy A. Oxide spintronics. IEEE Transactions on Electron Device,2007, 54(5): 1003-1023
    [16] Shapira Y, Oliveira N F, Ridgley D. H et al. Magnetoresistance and Hall effect near the metal-insulator transition of Cd1-xMnxSe. Phys. Rev B, 1986, 34: 4187–4198
    [17] Wojtowicz T, Dietl T, Sawicki M et al. Metal-Insulator Transition in Semimagnetic Semiconductors. Phys. Rev. Lett, 1986, 56: 2419–2422
    [18] Ohno H et al. Proceedings of the 23rd international conference on physics of semiconductors. Berlin, 1996, World Scienctific, Singapore, 43-51
    [19] Macdonald A H, Schiffer P, Samarth N. Ferromagnetic semiconductors: moving beyond (Ga,Mn)As. Nat. Mater, 2005, 4: 195-202
    [20] Ohno H, Shen A, Matsukura F, et al. (Ga,Mn)As: a mew ferromagnetic semiconductor basede on GaAs. Appl. Phys. Lett, 1996, 69: 363-365
    [21] Lee B, Jungwirth T, Macdonald A H. Ferromagnetism in diluted magnetic semiconductor spintronics. Semicond Sci &Tech, 2002, 17: 393-403
    [22] Min B I, Park M S, Park J H. The search for new spintronic materials: half-metallic antiferromagnets and diluted magentic semiconductors. J. Phys.:condens. Mater, 16: S5509-S5516
    [23] Can be seen from Science, 2005, 309: 82
    [24] Fukumura T, Toyosaki H, Yamada Y. Magnetic oxide semiconductors. Semicond Sci &Tech, 2005, 20: S103-S111
    [25] Ueda K, Tabata H, Kawai T. Magnetic and electric properties oftransition-metal-doped ZnO films. Appl. Phys. Lett, 2001, 79(7): 988-990
    [26] Park J H, Kim M G, Jang H M, et al. Co-metal clusters as the origin of feromagnetism in Co-doped ZnO thin films. Appl. Phys. Lett, 2004, 84(8):1338-1340
    [27] Lawers G, Risbud A S, Ramirez A P, Seshadri R. Absence of ferromagnetism in Co and Mn substituted polycrystalline ZnO. Phys. Rev B, 2005, 71: 045201
    [28] Chambers S A, Droubay T C, Wang C M, Rosso K M, Heald S M, Schwartz D A, Kittilstved K R, Gamelin D R. Ferromagnetism in oxide semiconductors. Mater Today, 2006, 9: 28-35
    [29] Coey J M D, Sanvito S. Magnetic semiconductors and half-metals. J. Phys. D: Appl. Phys, 2004, 37: 988-993
    [30] Prellier W, Fouchet A, Mercey B. Oxide-diluted magnetic semiconductors: a review of the experimental status. J Phys.: Condens. Matt, 2004, 15(37): R59-R74
    [31] Venkatesan M, Fitzgerald C B, Coey J M D. Unexpected magnetism in a dielectric oxide. Nature, 2004, 430(5): 630
    [32] Hong N N, Sakai J, Poirot N, Brize V. Room-temperature ferromagnetism obseved in undoped semiconducting and insulating oxide thin films. Phys. Rev B 2006, 73: 132404
    [33] Sundaresan A, Bhargavi R, Rangarajan N, Siddesh U, Rao C N R. Ferromagnetism as a universal feasure of nanoparticles of the otherwise nonmagnetic oxides. Phys. Rev B, 2006, 74:161306(R)
    [34] Ren Z H, Xu G, Wei X, et al. Room-temperature ferromagnetism in Fe-doped PbTiO3 nanocrystals. Appl. Phys. Lett, 2007, 91: 063106
    [35] Song C, Zeng F. Shen Y X, et al. Local Co structure and ferromagnetism in ion-implanted Co-doped LiNbO3. Phys. Rev B, 2006, 73:172412
    [36] Zhao T, Shinde S. R, Ogale S B, et al. Electric field effect in diluted magnetic insulator anatase Co: T. Phys. Rev. Lett, 2005, 94: 126601
    [37] Mcenroe S A, Stiglitz B C, Harrison R J, Robinson P, Fabian K, Mccammon C. Magnetic exchange bias of more than 1 Tesla in a natural mineral intergrowth. Nat. Nanotech, 2007, 2: 631-634
    [38] Dietl T. Ferromagnetic semiconductors. Semicond Sci & Tech, 2002, 17: 377-392
    [39] Fukumura T, Yamada, Toyosaki, Hasegawa T, Koinuma H, Kawasaki M. Exploration of oxide-based diluted magnetic semiconductors toward transparent spintronics. Appl. Surf. Sci, 2004, 223(1-3): 62-67
    [40] Janisch R, Gopal P, Spaldin A. Transition metal-doped T and ZnO-present status of the field. J.Phys.:Condens. Matter, 2005, 17: R657-R689
    [41] Chambers S A, Droubay T, Wang C M, et al. Clusters and magnetism in epitaxial Co-doped T anatase. Appl. Phys. Lett, 2003, 82:1257-1259
    [42] Kim D H, Yang J S, Lee K W, et al. Formation of Co nanoclusters in epitaxial Ti0.96Co0.04O2 thin films and their ferromagnetism. Appl. Phys. Lett, 2002, 13: 2421-2423
    [43] Kim J. Y, Park J H, Park B G, et al. Ferromagnetism induced by clustered Co in Co-doped anatase T thin films, Phys. Rev. Lett, 2003, 90(1): 017401
    [44] Mamiya K, Koide T, Fujimori A, et al. Indication of intrinsic room-temperature ferromagnetism in Ti1-xCoxO2 thin film: An x-ray magnetic circular dichroism study. Appl. Phys. Lett, 2006, 89: 062506
    [45] Chai J W, Pan J S, Wang S J, et al. Annealing temperature dependence of ferromagnetism of rutile Co-T(100). Appl. Phys. Lett, 2005, 86: 222505
    [46]冯端,金国均凝聚态材材学,北京:高等指育出版社,2003年
    [47]黄昆(原著),韩汝琦(改编),固稀材材学,北京:高等指育出版社,1988年
    [48] Han S J, Song J W, Yang C H, et al. A key to room-temperature ferromagnetism in Fe-doped ZnO: Cu. Appl. Phys. Lett, 2002, 81: 4212-4214
    [49] Shim J H, Hwang T, Lee S, et al. Origin of ferromagnetism in Fe- and Cu-codopedZnO. Appl. Phys. Lett, 2005, 86: 082503
    [50] Zhou S Q, Potzger K, Talut G, et al. Fe-implanted ZnO: magnetic precipiatates versus dilution. J. Appl. Phys, 2008, 103: 023902
    [51] Weyer G, Gunnlaugsson H P, Mantovan R, et al. Defect-related local magnetism at dilute Fe atoms in ion-implanted ZnO. J. Appl. Phys, 2007, 102:113915
    [52] Sharma P, Gupta A, Rao K V, et al. Ferromagnetism above room temperature in bulk and transparent thin films of Mn-doped ZnO. Nat. Mater, 2003, 21: 673-677
    [53] Kittilstved K R, Gamelin D R, Activation of high-Tc ferromagntism in Mn2+-doped ZnO using amines. J Am Chem Soc, 2006, 127: 5292-5293
    [54] Kittilstved K R, Norberg N S, Gamelin D R. Chemical manipulation of high-Tc ferromagnetism in ZnO diluted magnetic semiconductors. Phys. Rev. Lett, 2005, 94: 147209
    [55] Kundaliya D C, Ogale S B, Lofland S E, et al. On the origin of high- temperture ferromagnetism in the low-temperature-processed Mn-Zn-O system. Nat Mater, 2004, 3: 709-714
    [56] Gafcfa M A, Gonzalez M L R, Quesada A, Kramer J L C, Fernandez J F, et al. Interface double exchange ferromagnetism in the Mn-Zn-O system: New class of biphase magnetism. Phys. Rev. Lett, 2005, 94: 217206
    [57] Kramer J L C Briones F, Fernandez J F, Caballero A C, et al. Nanostructure and magnetic properties of the MnZnO sysem a room temperature magnetic semconductor?. Nanotechnology, 2005, 16: 214-218
    [58] Zhang J, Skomski R, Sellmyer, Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO. J. Appl. Phy, 2005, 97: 10D303
    [59] Luo J, Liang J K, Liu Q L, et al. Structure and magnetic properties of Mn-doped ZnO nanoparticles. J. Appl. Phy, 2005, 97: 086106
    [60] Coey J M D, Venkatesan M, Fitzgerald C B, Donor impurity band exchange in dilute ferromagntic oxide. Nat. Mater, 2005, 4:173-179
    [61] Kaminski A, Sarma S D. Polaron percolation in diluted magnetic semiconductors. Phys. Rev. Lett, 2002, 88: 247202
    [62] Kaminski A, Galitski V M, Sarma S D. Ferromagnetic and random spin ordering in dilute magnetic semiconductors. Phys. Rev B, 2004, 70:115216
    [63] Philip J, Punnoose A, Kim B I, et al. Carrier-controlled ferromagnetism in transparent oxide semiconductors. Nat. Mater, 2007, 5: 298:304
    [64] Priour D J, Sarma S D, Phase diagram of the disordered RKKY model in diluted magnetic semiconductors. Phys. Rev. Lett, 2006, 97: 127201
    [65] Coey J M D, Douvalis A P, Fitzgerald C B, Venkatesan M, Ferromagnetism in Fe-doped SnO2 thin films. Appl. Phys. Lett, 2004, 84: 1332-1334
    [66] Kittilstved K, Liu W K, Gamelin D R. Electronic structure origins of polarity-dependent high-TC ferromagnetism in oxide-diluted magnetic semiconductors. Nat. Mater, 2006, 5: 291-297
    [67] Wolff P A, Bhatt R N, Durst A C. Polaron-polaron interactions in diluted magnetic semiconductors. J. Appl. Phys, 1996, 79(8): 5196-5198
    [68] Bergqvist L, Eriksson O, Kudrnovsky J, et al. Magnetic percolation in diluted magnetic semiconductors. Phys. Rev. Lett, 2004, 93: 137202
    [69] Venkatesan M, Fitzgerald C B, Lunney J G, Coey J M D. Anisotropic ferromagnetism in substituted Zinc oxide. Phys. Rev. Lett, 2004, 93: 177206
    [70] Bryan J D, Santagngelo S A, Keveren S C, Gamelin D R. Activation of high-Tc feromagnetism in Co2+:T and Cr3+:T nanorods and nanocrystals by grain boundary defects. J. Am. Chem. Soc, 2005, 127: 15568-15574
    [71] Norberg N S, Kittilstved K R, Amonette J E, Kukkadapu R K, Schwartz D A, Gamelin D R. Synthesis of colloidal Mn2+:ZnO quantum dots and high-Tc ferromagentic nanocrystalline thin films. J. Am. Chem. Soc, 2004, 126: 9387-9398
    [72] Schwartz D A, Gamelin D R. Reversible 300 K ferromagnetic ordering in a diluted magnetic semiconductor. Adv. Mater, 2004, 16: 23-24
    [73] Ding Y, Han W Q, Lewis. Enhanced magnetism in Fe-doped T anatase nanorods. J. Appl. Phys, 2007, 102(12): 123902
    [74] Zhang X, Wang W H, Li L Y, et al. Effect of oxygen partical pressure on the ferromagnetism of Cr-doped T films. J. Phy. D: Appl. Phys, 2008, 41: 015005
    [75] Ramachandran S, Narayan J, Prater J T. Effect of oxygen annealing on Mn doped ZnO diluted magnetic semiconductors. Appl. Phy. Lett, 2006, 88: 242503
    [76] Hong N H, Sakai J, Prellier W, et al. Ferromagnetism in transition-metal-doped T thin films. Phys. Rev B, 2004, 70:195204
    [77] Zhao Y G, Shinde S R, Ogale S B, et al. Co-doped La0.5Sr0.5TiO3 diluted magnetic oxide system with high Curie temperature. Appl. Phys. Lett, 2003, 83: 2199-2201
    [78] Zhang S X, Ogale S B, Kundaliya D C, et al. Search for ferromagnetism in conductive Nb:SrTiO3 with magnetic transition element (Cr, Co, Fe, Mn) dopants. Appl. Phys. Lett, 2006, 89: 012501
    [79] Droubay T, Heald S M, Shutthanandan V, et al. Cr-doped T anantase: A ferromagnetic insulator, J. Appl. Phys, 2005, 97: 046103
    [80] Griffin K A, Pakhomov A B, Wang C M, Heald S M, Krishnan K M. Cobalt-doped anatase T: a room temperature dilute magnetic dielectric material. J. Appl. Phys, 2005, 97: 10D320
    [81] Meiklejohn W H, Bean C P. New magnetic anisotropy. Phys. Rev, 1956, 102: 1413
    [82] Nogues J, Sort J, Langlais V, Skumryev V, Surinach S, Munoz J S, Baro M D. Exchange bias in nanostructures. Phys Rep, 2005, 422: 65-117
    [83] Kiwi M. Exchange bias theory. J Magn & Magn Mater, 2001, 234: 584-595
    [84] Nogues J, Schuller I K. Exchange bias. J Magn & Magn Mater, 1999, 192: 203-232
    [85] Li K B, Wu Y H, Guo Z B, et al. Exchange coupling and its applications in magnetic data storage, J. Nanosci & Nanotech, 2007, 7:13-45
    [86] Lin H M, Hsu C M, Yao Y D, et al. Synthesis and exchange bias effect in Co/CoNnanocomposites, Nanostruct. Mater, 1995, 6 :977
    [87] De Toro J A, Andres J P, Gonzalez J A, et al. Exchange bias and nanoparticle magnetic stability in Co-CoO composites, Phys Rev B, 2006, 73(9) : 094449
    [88] Yi J B, Ding J, Zhao Z L, Liu B H, High coercivity and exchange coupling of Ni/NiO nanocomposite film, J.Appl. Phys, 2005, 97: 10K306
    [89] Wang H, Zhu T, Zhao K, et al, Surface spin glass and exchange bias in Fe3O4 nanoparticles compacted under high pressure, 2004, 70 : 092409
    [90] Zheng R K, Wen G H, Fung K K, Zhang X X, Giant exchange bias and the vertical shifts of hysteresis loops inγ-Fe2O3-coated Fe nanoparticles, J. Appl. Phys, 2004, 95(9): 5244-5246
    [91] Aprile C, Corma A, Garcia H, Enhancement of the photocatalytic activity of T through spatial structuring and particle size control: from subnanometric to submillimetric length scale. Phys. Chem. Chem. Phys, 2008, 10: 769-783
    [92] Valentin D C, Finazzi E, Pacchioni G, et al. N-doped T: Theory and experiment. Chem. Phys, 2007, 339: 28-35
    [93] Janisch R, Gopal P, Spaldin N A. Transition metal-doped T and ZnO-present status of the field. J. Phys: Conden Matt, 2005, 17: R657-R689
    [94] Ni M, Leung M K H, Leung D Y C, et al. A review and recent development in photocatalytic water-splitting using T for hydrogen production. Renew & Sust Energy Reviews, 2007, 11: 401-425
    [95] Batzill M, Diebold U. The surface and materials science of tin oxide. Prog. Surf. Sci, 2005, 79: 47-154
    [96] Eranna G, Joshi B C, Runthala D P, et al. Oxide materials for development of integrated gas sensors- A comprehensive review. Critcal Reviews solid Stat & Mater Sci, 2004, 29: 111-188
    [97] Hayamizu S, Tabata H, Tanaka H et al. Preparation of crystallized zinc oxide films on amorphous glass substrates by pulsed laser deposition. J. Appl. Phys, 1996, 80:787–789
    [98] Wu O K,Kamath G S,Radford W A et a1. Chemical doping of HgCdTe by molecular-beam epitaxy. J. Vac. Sci. Techno1, 1990, 8: 1034-1038
    [99] Yang Q H,Li C,Yuan S D et al. Epoxidation of Styrene on a Novel Titanium–Silica Catalyst Prepared by Ion Beam Implantation. J. Catal, 1999, 183: 128–130
    [100] Gorla C R, Emanetoglu N W, Liang S, et al. Structure, Optical, and surface acoustic wave properties of epitaxial ZnO films grown on ( 011? 2) sapphire by metalorganic chemical vapor depostion. J. Appl. Phys, 1998, 85: 2595–2597
    [101] Rykov A I, Nomura K, Sakuma J, et al. Dilution and clustering of Fe in the rutile phases of TiO2 and SnO2. Phys. Rev B, 2008, 77: 014302
    [102] Wang Y Q, Yuan S L, Song Y X, et al. Magnetism in Mn and Co doped ZnO bulk samples. Chin. Sci. Bull, 2007, 52: 1019-1023
    [103] Hays J, Punnoose A, Baldner R, et al. Relationship between the structural and magnetic properties of Co-doped SnO2 nanoparticles. 2005, 72: 075203
    [104] Punnoose A, Hays J, Thurber A, et al. Development of high-temperature ferromagnetism in SnO2 and paramagnetism in SnO by Fe doping. Phys. Rev B, 2005, 72: 054402
    [105] Hashimoto K, Irie H, Fujishima A. T photocatalysis: A historical overview and future prospects. Japan. J. Appl. Phys, 2005, 44: 8269-8285
    [106] Varghese O K, Grimes C A. Metal oxide nanoarchitectures for environmental sensing. J Nanoscience & Nanotechnology, 2003, 3: 277-293
    [107] Wang Z J, Tang J K, Tung L D, Zhou W L, Spinu L. Ferromagnetism and transport properties of Fe-doped reduced-rutile T thin films. 2003, 93: 7870-7872
    [108] Kaspar T C, Droubay T, Shutthanandan V, Heald S M, Wang C M, McCready D E, Braya J D, Gamelin D R, et al. Ferromagnetism and structure of epitaxialCr-doped anatase T thin films. Phys. Rev B, 2006, 73: 155327
    [109] Manivannan A, Glaspell G, Seehra M S. Controlled transformation of paramagnetism to room-temperature ferromagnetism in cobalt-doped titanium dioxide. J. Appl. Phys, 2003, 94: 6994-6996
    [110] Balcells L, Frontera C, Sandiumenge F, et al. Absence of ferromagnetism in Fe-doped T nanoparticles. Appl. Phys. Lett, 89: 122501
    [111] Glaspell G, Manivannan A. Sol-gel synthesis and magnetic studies of titanium dioxide doped with 10% M (M=Fe, Mn and Ni). J. Clust. Sci, 2005, 16: 501-513
    [112] Zhu S, Wang L M, Zu X T, Xiang X. Optical and magnetic properties of Ni nanoparticles in rutile formed by Ni ion implantation. Appl. Phys. Lett, 2006, 88: 043107
    [113] Ogale S, Kundaliya D, Mehraeen S, et al. Chemical inhomogeneity and mixed-state ferromagnetism in diluted magnetic semiconductor Co:T. Chem Mater, 2008, 20: 1344-1352
    [114] Soo Y L, Kioseoglou G, Kim S, et al. Local environment surrounding magnetic impurity atoms in a structural phase transition of Co-doped T nanocrystal ferromagnetic semiconductors. Appl. Phys. Lett, 2002, 81: 655-657
    [115] Liu F M, Wang T M, Li J Q, et al. Structural, optical and magnetic properties of a Mn thin film sandwiched between T films prepared by magnetron sputtering. J Magn & Magn Mater, 2002, 251: 245-250
    [116] Jeong E K, Hozer J C, Carlsson A E, et al. Highly symmetric Mn sites in icosahedral Ti-Mn, Phys. Rev. B, 1990, 41: 1695
    [117] Mofor A C, Shaer A E, Bakin A, et al. Magnetic property investigations on Mn-doped ZnO layers on sapphire. Appl. Phys. Lett, 2005, 87: 062501
    [118] Fukumura T, Jin Z W, Kawasaki M, et al. Magnetic properties of Mn-doped ZnO. Appl. Phys. Lett, 2001,78: 958-960
    [119] Jayakumar O D, Salunke H G, Kadam R M, et al. Magnetism in Mn-doped ZnOnanoparticles prepared by a co-precipitation method. Nanotechology, 2006, 17: 1278-1285
    [120] J. Spalet, A. Lewichki, Z. Tarnawski, et al. Exchange energy, magnetization, and Raman scattering of (Cd, Mn)Se. Phys. Rev. B 29: 5634 (1984)
    [121] Sato. K, Yoshida H. K. Stabilization of Ferromagnetic States by Electron Doping in Fe, Co- or Ni-Doped ZnO. Jpn. J. Appl. Phys, 2001,40: L334-336
    [122] Jung S W, An S J, Yi G C et al. Ferromagnetic properties of Zn1–xMnxO epitaxial thin films. Appl. Phys. Lett, 2002, 80: 4561-4563
    [123] Garcia M A, Ruiz-Gonzalez M L, Quesada A, Costa-Kramer J L, et al. Interface double-exchange ferromagnetism in the Mn-Zn-O system: New class of biphase magnetism. Phys. Rev. Lett, 2005, 94: 217206
    [124] Eid K F, Stone M B, Ku K C, et al. Exchange biasing of the ferromagnetic semiconductor Ga1-xMnxAs. Appl. Phys. Lett, 2004, 85: 1556-1558
    [125] Zheng R K, Liu H, Zhang X X, et al. Exchange bias and the origin of magnetism in Mn-doped ZnO tetrapods. Appl. Phys. Lett, 2004, 85: 2589-2591
    [126] Wang J F, Cai J N, Lin Y H, Nan C W. Room-temperature ferromagnetism observed in Fe-doped NiO. Appl. Phys. Lett, 2005, 87: 202501
    [127] Huang P H, Huang H H, Lai C H. Coexistence of exchange-bias fields and vertical magnetization shifts in ZnCoO/NiO system. Appl. Phys. Lett, 2007, 90: 062509
    [128] Seehra M S, Dutta P, Singh V, Zhang Y, Wender I. Evidence for room temperature ferromagnetism in CuxZn1-xO from magnetic studies in CuxZn1-xO/CuO composites. J. Appl. Phys, 2007, 101: 09H107
    [129] Tian Z M, Yuan S L, Wang Y Q, et al. Magnetic properties of Mn-doped T bulk samples. J. Phys. D: Appl. Phys,2008, 41: 055006
    [130] Saeki H, Tabata H, Kawai T. Magnetic and electric properties of vanadium doped ZnO films. Solid Stat Comm, 2001, 120: 439-443
    [131] Hong N H, Sakai J, Hassini A. Magnetic properties of V-doped ZnO thin fims. J.Appl. Phys, 2005, 97: 10D312
    [132] Ramachandran S, Tiwari A, Narayan J, Prater J T. Epitaxial growth and properties of Zn1-xVxO diluted magnetic semiconductor thin films. Appl. Phys. Lett, 2005, 87(17): 172502
    [133] Zhou S Q, Potzger K, Reuther H, et al. Absence of ferromagnetism in V-implanted ZnO single crystals. J. Appl. Phys, 2007, 101: 09H109
    [134] Liu S H, Hsu H S, Lin C R, Lue C S, Huang J C A. Effects of hydrogenated annealing on structural defects, conductivity, and magnetic properties of V-doped ZnO powders. Appl. Phys. Lett, 2007, 90: 222505
    [135] Hong N H, Sakai J, Hassini A. Ferromagnetism at room temperature with a large magnetic moment in anatase V-doped T thin films. Appl. Phys. Lett, 2004, 84(14): 2602-2604
    [136] Hong N H, Ruyter A, Gervais F, Prellier W, Sakai J. Magnetic structure of V: T and Cr: T thin films from magnetic force microscopy measurements. J. Appl. Phys, 2005, 97:10D323
    [137] Gao Y, Thevuthasan S, McCready D E, Engelhard M. MOCVD growth and structure of Nb- and V- doped T films on sapphire. J. Crys. Growth, 212(1-2): 178-190
    [138] Du X S, Li Q X, Su H B, Yang J L. Electronic and magnetic properties of V-doped anatase T from first principles. Phys. Rev B, 2006, 74: 233201
    [139] Xu J P, Lin Y B, Lu Z H, et al. Enhanced ferromagnetism in Mn-doped T films during the structural phase transition, Solid State Comm, 2006, 140(11-12): 514-518
    [140] Maensiri S, Laokui P, Klinkaewnarong J, A simple synthesis and room-temperature magnetic behavior of Co-doped anatase T nanoparticles. J Magn & Magn Mater, 2006, 302(2): 448-453
    [141] Shin S, Suga S, Taniguchi M, Fujisawa M, et al. Vacuum-ultraviolet reflectanceand photoemission study of the metal-insulator phase transition in VO2, V6O13, and V2O3. Phys. Rev B, 1990, 41: 4993-5009
    [142] Xiao Z R, Guo G Y, Lee P H, Hsu H S, et al. Oxygen vacancy induced ferromagnetism in V2O5-x. J. Phys. Soc. Japan, 2008, 77(2): 023706
    [143] Krusin-Elbaum L, Newns D W, Zeng H, Derycke V, Sun J Z, Sandstrom R. Room-temperature ferromagnetism nanotubes controlled by electron or hole doping. Nature, 2004, 431: 672-676
    [144] Kimura H, Fukumura T, Koinuma H, et al. Fabrication and characterization of Mn doped SnO2 thin films. Physica E, 2001, 10(1-3): 265-267
    [145] Fitzgerald C B, Venkatesan M, Douvalis A P, et al. SnO2 doped with Mn, Fe or Co: Room temperature dilute magnetic semiconductors. J. Appl. Phys, 95(11): 7390-7392
    [146] Wang X L, Dai Z X, Zeng Z. Search for ferromagnetism in SnO2 doped with transition metals (V, Mn, Fe, and Co). J. Phys: Cond Matter, 2008, 20(4): 045214
    [147] Duan L B, Rao G H, Yu J, et al. Structural and magnetic properties of chemically synthesized Sn1-xMnxO2 nanocrystalline powders. J. Appl. Phys, 2007, 101(6): 063917
    [148] Gao K H, Li Z Q, Liu X J, Song W, Liu H, Jiang E Y, Bulk Sn1-xMnxO2 magnetic semiconductors without room-temperature ferromagnetism, Solid State Comm, 2006, 138(4): 175-178
    [149] Kuang A L, Liu X C, Lu Z L, et al. Room-temperature ferromagnetism in Mn-doped SnO2 diluted magnetic semiconductor. Acta Phys Sinica, 2005, 54(6): 2934-2937
    [150] Hays J, Punnoose A, Baldner R, et al. Relationship between the structural and magnetic properties of Co-doped SnO2 nanoparticles. Phys. Rev B, 2005, 72(7): 075203
    [151] Wickham D G, Menuyk N and Dwight K. Evidence for canted magnetic momentsin manganous stannate (Mn2SnO4). J. Phys. Chem. Solids, 1961, 20: 316-318
    [152] Wang J B, Huang G J, Zhong X L, et al. Raman scattering and high temperature ferromagnetism of Mn-doped ZnO nanoparticles. Appl. Phys. Lett, 2006, 88(25): 252502
    [153] Summerfelt S R, Carter C B, Kinetics of NiFe2O4 precipitation in NiO, J Am Cera Soc, 1992, 75(8): 2244-2250
    [154] Sort J, Popa A, Rodmacq B, Dieny B, Exchange-bias properties in permalloy deposited onto a Pt/Co multilayer, Phys. Rev B, 2004, 70:174431
    [155] Tang Y K, Sun Y, Cheng Z H, Exchange bias associated with phase separation in the perovskite cobaltite La1-xSrxCoO3, Phys Rev B, 2006, 73: 174419
    [156] Fiorani D, Bianco L D, Testa A M, et al. Exchange bias in disordered granular systems, J. Phys.: Condens. Matt, 2007, 19: 225007
    [157] Jiang J Z, Goya G F, Rechenberg H R. Magnetic properties of nanostructured CuFe2O4, J Phys: Condens Matter,1999, 11: 4063.

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