掺杂SnO_2稀磁材料的微观结构及铁磁性研究
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摘要
掺杂SnO_2稀磁材料优异的物化性能,特别是巨磁矩和高居里温度的出现,使其在稀磁半导体领域展现出极大的应用潜力和理论研究价值。然而长期以来, SnO_2稀磁材料的铁磁性来源及物理机制都是未能解决的两大关键问题。为此,本文采用磁控溅射和溶剂热法分别制备了Co掺杂SnO_2稀磁薄膜和Co/Zn掺杂SnO_2纳米棒,系统研究了工艺参数对材料微观结构和磁性能的影响,揭示微观结构和磁性能的关系,从实验和理论两方面阐述了SnO_2基稀磁材料的上述问题。为澄清SnO_2基稀磁材料的铁磁性来源,本文采用基于同步辐射的X射线吸收精细结构技术及相关理论计算,深入分析了掺杂元素的局域结构。结果表明SnO_2稀磁薄膜和纳米棒为金红石结构的SnO_2相,掺杂元素成功替代了SnO_2晶格中的Sn元素,由此证明所制备的掺杂SnO_2薄膜和纳米棒为具有本征铁磁特性的稀磁材料。
在探讨SnO_2基稀磁材料铁磁性物理机制上,本文通过制备具有室温铁磁性的绝缘态Co掺杂SnO_2(Co-SnO_2)稀磁薄膜,有效分离了结构缺陷和载流子对材料磁性能的影响。首先通过使用不同靶材、改变薄膜沉积参数、调节SnO_2缓冲层厚度,证明结构缺陷对Co-SnO_2稀磁薄膜铁磁性具有调制作用。在此基础上,采用不同工艺热处理和N元素共掺杂工艺,分别研究了施主缺陷和受主缺陷(即点缺陷)对Co-SnO_2稀磁薄膜铁磁性的调节,确定点缺陷是影响铁磁性的根本因素,从而成功证明了束缚磁极化子(BMP)模型在解释掺杂SnO_2稀磁材料铁磁性机制上的合理性。
为进一步验证BMP模型在不同维度SnO_2基稀磁材料中的普适性,本文采用溶剂热法制备了室温铁磁性的Co-SnO_2纳米棒,证实纳米棒中同时存在由结构缺陷调制的长程铁磁有序和邻近Co离子间的反铁磁耦合,该结果同样符合BMP模型的理论机制。此外,在非磁性Zn元素掺杂SnO_2纳米棒中还观察到明显的铁磁性,结合微观结构分析表明材料的铁磁性来源于Zn掺杂诱导的锡空位,铁磁性强弱与锡空位的浓度密切相关。该结果为基于d0机制的第一性原理计算提供了实验数据支持,并开拓了设计新型SnO_2基稀磁材料的思路。
Transition-metal doped SnO_2 is considered as an important candidate material in the field of diluted magnetic semiconductor due to its excellent physical and chemical properties. Particularly, the discoveries of a giant magnetic moment and high Curie temperature in Co-doped SnO_2 films have inspired tremendous experimental and theoretical investigations. Up to date, the ferromagnetic origin and related physical mechanism in SnO_2-based diluted magnetic material have not been fully understood. In this dissertation, Co-doped SnO_2 films and Co/Zn-doped SnO_2 nanorods are prepared by magnetron sputtering and solvethermal methods, respectively. Through changing experimental conditions, we systematically investigate the microstructure and magnetic properties of the materials. These researches focus on the local structure of the doping element in SnO_2 and discuss the correlations between magnetic properties and the microstructure. Based on the above studies, the ferromagnetic origin as well as the related mechanism is further explained.
To clear the ferromagnetic origin, X-ray abosorption fine structure characterization with first-principle calculations are used to investigate the local environment of doped elements in SnO_2. The results show that the doped elements have successfully substituted for Sn elements in SnO_2 lattice without forming secondary phases, which confirms the intrinsic nature of ferromagnetism in doped SnO_2 diluted magnetic materials.
Room-temperature ferromagnetism is achieved in insulating Co-SnO_2 diluted magnetic films. The investigations on insulating films efficiently separate the influences of structural defects and free carriers on the magnetism of the materials, which is helpful for clarifying the ferromagnetic mechanism. Sputtering targets, deposition parameters and buffer layer thickness are changed to adjust the microstructure and magnetic properties of Co-SnO_2 films. The experimental results demonstrate the mediation effect of structural defects on the long-term ferromagnetic ordering. Furthermore, various post-annealing processes are used to vary the concentrations of oxygen vacancies and Sn interstitials in Co-SnO_2 films, which confims the crucial roles of donor defects in tuning magnetic properties. Additionally, nitrogen is codoped with Co to create acceptor defects in (Co,N)-codoped SnO_2 films. The dependence of ferromagnetism on nitrogen concentration implies that the acceptor defect is another key factor in mediating magnetism in doped SnO_2 materials. According to the above analyses, the ferromagnetic mechanism in SnO_2-based diluted magnetic materials is reasonabley explained using bound magnetic polaron (BMP) mechanism based on the presence of donor and acceptor defects.
To further verify the BMP model in different dimensional SnO_2-based diluted magnetic materials, we have successfully synthesized room–temperature ferromagnetic Co-doped SnO_2 nanorods via solvethermal methods. Magnetic property measurements indicate that the long-range ferromagnetic ordering mediated by structural defects coexists with the antiferromagnetic coupling between adjacent Co ions in Co-doped SnO_2 nanorods. Such result is consistent with the description of BMP model. Moreover, room-temperature ferromagnetism is observed in nonmagnetic Zn element doped SnO_2 nanorods. Combining with microstructure analyses, it is found that the ferromagnetism of the material originates from the Zn doping-induced Sn vacancies. The saturated magnetization is sensitive to the concentration of Sn vacancies, and can be well tunned by modifying the content of Zn dopants. This study not only offers experimental support to the first-principle calculations of d0 mechanism, but also opens a new way to fabricate room-temperature SnO_2-based diluted magnetic materials.
在探讨SnO_2基稀磁材料铁磁性物理机制上,本文通过制备具有室温铁磁性的绝缘态Co掺杂SnO_2(Co-SnO_2)稀磁薄膜,有效分离了结构缺陷和载流子对材料磁性能的影响。首先通过使用不同靶材、改变薄膜沉积参数、调节SnO_2缓冲层厚度,证明结构缺陷对Co-SnO_2稀磁薄膜铁磁性具有调制作用。在此基础上,采用不同工艺热处理和N元素共掺杂工艺,分别研究了施主缺陷和受主缺陷(即点缺陷)对Co-SnO_2稀磁薄膜铁磁性的调节,确定点缺陷是影响铁磁性的根本因素,从而成功证明了束缚磁极化子(BMP)模型在解释掺杂SnO_2稀磁材料铁磁性机制上的合理性。
为进一步验证BMP模型在不同维度SnO_2基稀磁材料中的普适性,本文采用溶剂热法制备了室温铁磁性的Co-SnO_2纳米棒,证实纳米棒中同时存在由结构缺陷调制的长程铁磁有序和邻近Co离子间的反铁磁耦合,该结果同样符合BMP模型的理论机制。此外,在非磁性Zn元素掺杂SnO_2纳米棒中还观察到明显的铁磁性,结合微观结构分析表明材料的铁磁性来源于Zn掺杂诱导的锡空位,铁磁性强弱与锡空位的浓度密切相关。该结果为基于d0机制的第一性原理计算提供了实验数据支持,并开拓了设计新型SnO_2基稀磁材料的思路。
Transition-metal doped SnO_2 is considered as an important candidate material in the field of diluted magnetic semiconductor due to its excellent physical and chemical properties. Particularly, the discoveries of a giant magnetic moment and high Curie temperature in Co-doped SnO_2 films have inspired tremendous experimental and theoretical investigations. Up to date, the ferromagnetic origin and related physical mechanism in SnO_2-based diluted magnetic material have not been fully understood. In this dissertation, Co-doped SnO_2 films and Co/Zn-doped SnO_2 nanorods are prepared by magnetron sputtering and solvethermal methods, respectively. Through changing experimental conditions, we systematically investigate the microstructure and magnetic properties of the materials. These researches focus on the local structure of the doping element in SnO_2 and discuss the correlations between magnetic properties and the microstructure. Based on the above studies, the ferromagnetic origin as well as the related mechanism is further explained.
To clear the ferromagnetic origin, X-ray abosorption fine structure characterization with first-principle calculations are used to investigate the local environment of doped elements in SnO_2. The results show that the doped elements have successfully substituted for Sn elements in SnO_2 lattice without forming secondary phases, which confirms the intrinsic nature of ferromagnetism in doped SnO_2 diluted magnetic materials.
Room-temperature ferromagnetism is achieved in insulating Co-SnO_2 diluted magnetic films. The investigations on insulating films efficiently separate the influences of structural defects and free carriers on the magnetism of the materials, which is helpful for clarifying the ferromagnetic mechanism. Sputtering targets, deposition parameters and buffer layer thickness are changed to adjust the microstructure and magnetic properties of Co-SnO_2 films. The experimental results demonstrate the mediation effect of structural defects on the long-term ferromagnetic ordering. Furthermore, various post-annealing processes are used to vary the concentrations of oxygen vacancies and Sn interstitials in Co-SnO_2 films, which confims the crucial roles of donor defects in tuning magnetic properties. Additionally, nitrogen is codoped with Co to create acceptor defects in (Co,N)-codoped SnO_2 films. The dependence of ferromagnetism on nitrogen concentration implies that the acceptor defect is another key factor in mediating magnetism in doped SnO_2 materials. According to the above analyses, the ferromagnetic mechanism in SnO_2-based diluted magnetic materials is reasonabley explained using bound magnetic polaron (BMP) mechanism based on the presence of donor and acceptor defects.
To further verify the BMP model in different dimensional SnO_2-based diluted magnetic materials, we have successfully synthesized room–temperature ferromagnetic Co-doped SnO_2 nanorods via solvethermal methods. Magnetic property measurements indicate that the long-range ferromagnetic ordering mediated by structural defects coexists with the antiferromagnetic coupling between adjacent Co ions in Co-doped SnO_2 nanorods. Such result is consistent with the description of BMP model. Moreover, room-temperature ferromagnetism is observed in nonmagnetic Zn element doped SnO_2 nanorods. Combining with microstructure analyses, it is found that the ferromagnetism of the material originates from the Zn doping-induced Sn vacancies. The saturated magnetization is sensitive to the concentration of Sn vacancies, and can be well tunned by modifying the content of Zn dopants. This study not only offers experimental support to the first-principle calculations of d0 mechanism, but also opens a new way to fabricate room-temperature SnO_2-based diluted magnetic materials.
引文
[1] Wolf S A, Awschalom D D, Buhrman R A, et al. Spintronics: A spin-based electronics vision for the future. Science, 2001, 294:1488-1495.
[2] Vonhelmolt R, Wecker J, Holzapfel B, et al. Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic-films. Phys. Rev. Lett., 1993, 71:2331-2333.
[3] Moodera J S, Kinder L R, Wong T M, et al. Large magnetoresistance at room-temperature in ferromagnetic thin-film tunnel-junctions. Phys. Rev. Lett., 1995, 74:3273-3276.
[4] Schmidt G, Ferrand D, Molenkamp L W, et al. Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor. Phys. Rev. B, 2000, 62:R4790-R4793.
[5] Cooley B J, Clark T E, Liu B Z, et al. Growth of magneto-optically active (Zn,Mn)Se nanowires. Nano Letters, 2009, 9:3142-3146.
[6] Bacaksiz E, Tomakin M, Altunbas M, et al. Structural, optical and magnetic properties of Cd(1-x)CoxS thin films prepared by spray pyrolysis. Physica B-Condensed Matter, 2008, 403:3740-3745.
[7] Bouloudenine M, Viart N, Colis S, et al. Antiferromagnetism in bulk Zn1-xCoxO magnetic semiconductors prepared by the coprecipitation technique. Appl. Phys. Lett., 2005, 87:052501.
[8] Jayakumar O D, Sudakar C, Persson C, et al. 1D morphology stabilization and enhanced magnetic properties of Co:ZnO nanostructures on codoping with Li: A template-free synthesis. Crystal Growth & Design, 2009, 9:4450-4455.
[9] Macdonald A H, Schiffer P, Samarth N. Ferromagnetic semiconductors: Moving beyond (Ga,Mn)As. Nat. Mater., 2005, 4:195-202.
[10] Jungwirth T, Wang K Y, Masek J, et al. Prospects for high temperature ferromagnetism in (Ga,Mn)As semiconductors. Phys. Rev. B, 2005, 72:165204.
[11] Dehbaoui M, Benkhettou N, Benrekia R A. First principle calculation for structural properties and bowing parameter in Ga1-xMnxN materials. Mat. Sci. Semicon. Proc., 2008, 11:37-43.
[12] Bihler C, Gerstmann U, Hoeb M, et al. Manganese-hydrogen complexes in Ga1-xMnxN. Phys. Rev. B, 2009, 80:205205.
[13] Lussier A, Dvorak J, Idzerda Y U, et al. Comparative x-ray absorption spectroscopy study of Co-doped SnO2 and TiO2. J. Appl. Phys., 2004, 95:7190-7191.
[14] Hong N H, Sakai J, Prellier W, et al. Room temperature ferromagnetism in laser ablated transition-metal-doped TiO2 thin films on various types of substrates. Journal Of Physics D-Applied Physics, 2005, 38:816-821.
[15] Elamrani M, Lascaray J P, Diouri J. Fundamental Absorption Of Cd1-xMnxTe Crystals. Solid State Communications, 1983, 45:351-353.
[16] Diouri J, Lascaray J P, Elamrani M. Effect of the magnetic order on the optical-absorption edge in Cd1-xMnxTe. Phys. Rev. B, 1985, 31:7995-7999.
[17] Furdyna J K. Diluted Magnetic Semiconductors. J. Appl. Phys., 1988, 64:R29-R64.
[18] Ziese M, Thorntom M J. Spin electronics. Berlin: Springer, 2001.
[19]王学忠,陈辰嘉,王荣明,等. Cd1-xMnxTe的巨大法拉第旋转与激子跃迁.半导体学报, 1994, 15:333.
[20] Shinde S R, Ogale S B, Higgins J S, et al. Co-occurrence of superparamagnetism and anomalous Hall effect in highly reduced cobalt-doped rutile TiO2-δfilms. Phys. Rev. Lett., 2004, 92:166601.
[21] Xu Q Y, Hartmann L, Schmidt H, et al. Metal-insulator transition in Co-doped ZnO: Magnetotransport properties. Phys. Rev. B, 2006, 73:205342.
[22] Ohno H, Chiba D, Matsukura F, et al. Electric-field control of ferromagnetism. Nature, 2000, 408:944-946.
[23]王颖,湛永钟,许艳飞,等.稀磁半导体材料的研究进展及应用前景.材料导报, 2007, 21:20-23.
[24] Dietl T. Optical-properties of donor electrons in semimagnetic semiconductors. Journal of Magnetism and Magnetic Materials, 1983, 38:34-44.
[25] Furdyna J K. Electrical, optical, and magnetic-properties of Hg1-xMnxTe. Journal of Vacuum Science & Technology, 1982, 21:220-228.
[26] Ohno H, Shen A, Matsukura F, et al. (Ga,Mn)As: A new diluted magnetic semiconductor based on GaAs. Appl. Phys. Lett., 1996, 69:363-365.
[27] Ohno Y, Young D K, Beschoten B, et al. Electrical spin injection in a ferromagnetic semiconductor heterostructure. Nature, 1999, 402:790-792.
[28] Dietl T, Ohno H, Matsukura F, et al. Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science, 2000, 287:1019-1022.
[29] Sudakar C, Thakur J S, Lawes G, et al. Ferromagnetism induced by planar nanoscale CuO inclusions in Cu-doped ZnO thin films. Phys. Rev. B, 2007, 75:054423.
[30] Liu X J, Song C, Zeng F, et al. Strain-induced ferromagnetism enhancement in Co:ZnO films. J. Appl. Phys., 2008, 103:093911.
[31] Pan F, Song C, Liu X J, et al. Ferromagnetism and possible application in spintronics of transition-metal-doped ZnO films. Materials Science & Engineering R-Reports, 2008, 62:1-35.
[32] Krishnaiah G, Rao N M, Reddy B K, et al. EPR and magnetic properties of vapour phase grown Zn1-xCrxTe crystals. Physics Letters A, 2008, 372:6429-6433.
[33] Soundararajan D, Mangalaraj D, Nataraj D, et al. Ferromagnetism in Zn1-xCrxTe (x=0.05, 0.15) films grown on GaAs(100) substrate. Current Applied Physics, 2010, 10:771-775.
[34] Jiang F X, Xu X H, Zhang J, et al. Role of carrier and spin in tuning ferromagnetism in Mn and Cr-doped In2O3 thin films. Appl. Phys. Lett., 2010, 96:052503.
[35] Sudakar C, Dixit A, Kumar S, et al. Coexistence of anion and cation vacancy defects in vacuum-annealed In2O3 thin films. Scripta Materialia, 2010, 62:63-66.
[36] Higgins J S, Shinde S R, Ogale S B, et al. Hall effect in cobalt-doped TiO2-δ. Phys. Rev. B, 2004, 69:073201.
[37] Chen J, Rulis P, Ouyang L Z, et al. Vacancy-enhanced ferromagnetism in Fe-doped rutile TiO2. Phys. Rev. B, 2006, 74:235207.
[38] Lee H M, Kim S J, Shim I B, et al. Effects of Nb doping on the magnetism of anatase Fe-doped TiO2. Ieee Transactions on Magnetics, 2006, 42:2706-2708.
[39] Ueda K, Tabata H, Kawai T. Magnetic and electric properties of transition-metal-doped ZnO films. Appl. Phys. Lett., 2001, 79:988-990.
[40] Farley N R S, Edmonds K W, Freeman A A, et al. Magnetic properties of sol-gel-derived doped ZnO as a potential ferromagnetic semiconductor: A synchrotron-based. New Journal of Physics, 2008, 10:055012.
[41] Peleckis G, Wang X L, Dou S X. High temperature ferromagnetism in Ni-doped In2O3 and indium-tin oxide. Appl. Phys. Lett., 2006, 89:022501.
[42] Chambers S A, Droubay T, Wang C M, et al. Clusters and magnetism in epitaxial Co-doped TiO2 anatase. Appl. Phys. Lett., 2003, 82:1257-1259.
[43] Kim J H, Kim H, Kim D, et al. Magnetic properties of epitaxially grown semiconducting Zn1-xCoxO thin films by pulsed laser deposition. J. Appl. Phys., 2002, 92:6066-6071.
[44] Zener C. Interaction between the d-shells in the transition metals.2. ferromagnetic compounds of manganese with perovskite structure. Physical Review, 1951, 82:403-405.
[45] Sato K, Katayama-Yoshida H. Stabilization of ferromagnetic states by electron doping in Fe-, Co- or Ni-doped ZnO. Japanese Journal of Applied Physics Part 2-Letters, 2001, 40:L334-L336.
[46] Sato K, Katayama-Yoshida H. Material design for transparent ferromagnets with ZnO-based magnetic semiconductors. Japanese Journal of Applied Physics Part 2-Letters, 2000, 39:L555-L558.
[47] 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.
[48] Kasuya T. A theory of metallic ferromagnetism and antiferromagnetism on Zeners model. Progress of Theoretical Physics, 1956, 16:45-57.
[49] Yosida K. Magnetic properties of Cu-Mn alloys. Physical Review, 1957, 106:893-898.
[50] Ruderman M A, Kittel C. Indirect exchange coupling of nuclear magnetic moments by conducting electrons. Physical Review, 1954, 96:99-102.
[51] Liao L, Lu H B, Zhang L, et al. Effect of ferromagnetic properties in Al-doped Zn1-xCoxO nanowires synthesized by water-assistance reactive vapor deposition. J. Appl. Phys., 2007, 102:114307.
[52] Mounkachi O, Benyoussef A, El Kenz A, et al. Ab initio calculation of Zn0.8Mn0.2O1-yNy. Journal of Magnetism and Magnetic Materials, 2008, 320:2760-2765.
[53] Griffin K A, Pakhomov A B, Wang C M, et al. Intrinsic ferromagnetism in insulating cobalt doped anatase TiO2. Phys. Rev. Lett., 2005, 94:157204.
[54] Coey J M D, Venkatesan M, Fitzgerald C B. Donor impurity band exchange in dilute ferromagnetic oxides. Nat. Mater., 2005, 4:173-179.
[55] Venkatesan M, Fitzgerald C B, Coey J M D. Unexpected magnetism in a dielectric oxide. Nature, 2004, 430:630-630.
[56] Das Pemmaraju C, Sanvito S. Ferromagnetism driven by intrinsic point defects in HfO2. Phys. Rev. Lett., 2005, 94:217205.
[57] Bouzerar G, Ziman T. Model for vacancy-induced d(0) ferromagnetism in oxide compounds. Phys. Rev. Lett., 2006, 96:207602.
[58] Hong N H, Sakai J, Poirot N, et al. Room-temperature ferromagnetism observed in undoped semiconducting and insulating oxide thin films. Phys. Rev. B, 2006, 73:132404.
[59] Abraham D W, Frank M M, Guha S. Absence of magnetism in hafnium oxide films. Appl. Phys. Lett., 2005, 87:252502.
[60] Yu B L, Zhu C S, Gan F X. Exciton spectra of SnO2 nanocrystals with surficial dipole layer. Optical Materials, 1997, 7:15-20.
[61] Kimura H, Fukumura T, Kawasaki M, et al. Rutile-type oxide-diluted magnetic semiconductor: Mn-doped SnO2. Appl. Phys. Lett., 2002, 80:94-96.
[62] Ogale S B, Choudhary R J, Buban J P, et al. High temperature ferromagnetism with a giant magnetic moment in transparent Co-doped SnO2-δ. Phys. Rev. Lett., 2003, 91:077205.
[63] Gopinadhan K, Kashyap S C, Pandya D K, et al. Evidence of carrier mediated room temperature ferromagnetism in transparent semiconducting Sn1-xCoxO2-δthin films. Journal of Physics-Condensed Matter, 2008, 20:125208.
[64] Fitzgerald C B, Venkatesan M, Dorneles L S, et al. Magnetism in dilute magnetic oxide thin films based on SnO2. Phys. Rev. B, 2006, 74:115307.
[65] Hong N H, Sakai J. Ferromagnetic V-doped SnO2 thin films. Physica B-Condensed Matter, 2005, 358:265-268.
[66] Hong N H, Sakai J, Prellier W, et al. Transparent Cr-doped SnO2 thin films: Ferromagnetism beyond room temperature with a giant magnetic moment. Journal of Physics-Condensed Matter, 2005, 17:1697-1702.
[67] Coey J M D, Douvalis A P, Fitzgerald C B, et al. Ferromagnetism in Fe-doped SnO2 thin films. Appl. Phys. Lett., 2004, 84:1332-1334.
[68] Mathew X, Enriquez J P, Mejia-Garcia C, et al. Structural modifications of SnO2 due to the incorporation of Fe into the lattice. J. Appl. Phys., 2006, 100:073907.
[69] Archer P I, Radovanovic P V, Heald S M, et al. Low-temperature activation and deactivation of high-Curie-temperature ferromagnetism in a new diluted magnetic semiconductor: Ni2+-doped SnO2. Journal of the American Chemical Society, 2005, 127:14479-14487.
[70] 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.
[71] Gopinadhan K, Pandya D K, Kashyap S C, et al. Cobalt-substituted SnO2 thin films: A transparent ferromagnetic semiconductor. J. Appl. Phys., 2006, 99:126106.
[72] Bouaine A, Brihi N, Schmerber G, et al. Structural, optical, and magnetic properties of Co-doped SnO2 powders synthesized by the coprecipitation technique. J. Phys. Chem. C, 2007, 111:2924-2928.
[73] 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., 2004, 95:7390-7392.
[74] Hays J, Punnoose A, Baldner R, et al. Relationship between the structural and magnetic properties of Co-doped SnO2 nanoparticles. Phys. Rev. B, 2005, 72:075203.
[75] Wang W D, Wang Z J, Hong Y J, et al. Structure and magnetic properties of Cr/Fe-doped SnO2 thin films. J. Appl. Phys., 2006, 99:08m115.
[76] Sakuma J, Nomura K, Barrero C, et al. Mossbauer studies and magnetic properties of SnO2 doped with 57Fe. Thin Solid Films, 2007, 515:8653-8655.
[77] Rahman G, Garcia-Suarez V M, Hong S C. Vacancy-induced magnetism in SnO2: A density functional study. Phys. Rev. B, 2008, 78:184404.
[78] Zhou W, Liu L J, Wu P. Nonmagnetic impurities induced magnetism in SnO2. Journal of Magnetism and Magnetic Materials, 2009, 321:3356-3359.
[79]侯鹤岚.直流磁控溅射镀膜在玻璃涂层技术中的应用.真空, 2001:18-22.
[80]徐如人.无机合成化学.北京:北京高等教育出版社, 1991.
[81] Chen Z Q, Maekawa M, Kawasuso A, et al. Annealing process of ion-implantation-induced defects in ZnO: Chemical effect of the ion species. Journal of Applied Physics, 2006, 99:093507.
[82]王英华. X光衍射技术基础.北京:原子能出版社, 1993.
[83]黄新民.材料研究方法.哈尔滨:哈尔滨工业大学出版社, 2008.
[84]朱永法.纳米材料的表征与测试技术.北京:化学工业出版社, 2006.
[85]马礼敦,杨福家.同步辐射应用概论(第二版).上海:复旦大学出版社, 2001.
[86] Ankudinov A L, Ravel B, Rehr J J, et al. Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure. Physical Review B, 1998, 58:7565-7576.
[87]郁伟中.正电子物理及其应用.北京:科学出版社, 2003.
[88]彭成晓.正电子对ZnO和GaN宽带隙半导体中缺陷的研究[博士学位论文].合肥:中国科技大学, 2006.
[89] Chen Z Q, Maekawa M, Yamamoto S, et al. Evolution of voids in Al+-implanted ZnO probed by a slow positron beam. Physical Review B, 2004, 69:035210.
[90]陈海英.精密磁强计的发展现状及应用.现代仪器, 2000:5-7.
[91]陈培榕,邓勃.现代仪器分析实验与技术.北京:清华大学出版社, 2001.
[92] Tuan A C, Bryan J D, Pakhomov A B, et al. Epitaxial growth and properties of cobalt-doped ZnO on alpha-Al2O3 single-crystal substrates. Phys. Rev. B, 2004, 70:054424.
[93] Pan S S, Ye C, Teng X M, et al. Preparation and characterization of nitrogen-incorporated SnO2 films. Applied Physics a-Materials Science & Processing, 2006, 85:21-24.
[94] Chambers S A, Heald S M, Droubay T. Local Co structure in epitaxial CoxTi1-xO2-x anatase. Phys. Rev. B, 2003, 67:100401.
[95] Hong N H, Sakai J, Huong N T, et al. Role of defects in tuning ferromagnetism in diluted magnetic oxide thin films. Phys. Rev. B, 2005, 72:045336.
[96] Matsumoto Y, Murakami M, Shono T, et al. Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide. Science, 2001, 291:854-856.
[97] Song C, Geng K W, Zeng F, et al. Giant magnetic moment in an anomalous ferromagnetic insulator: Co-doped ZnO. Phys. Rev. B, 2006, 73:024405.
[98] Kim J Y, Park J H, Park B G, et al. Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films. Phys. Rev. Lett., 2003, 90:017401.
[99] Huang C L, Wang J J, Hsu C H. Influence of deposition pressure and rf power on the structure and electrical properties of Zr0.8Sn0.2TiO4 thin films prepared by rf magnetron sputtering. Journal of Vacuum Science & Technology B, 2007, 25:299-305.
[100] Straumal B B, Mazilkin A A, Protasova S G, et al. Magnetization study of nanograined pure and Mn-doped ZnO films: Formation of a ferromagnetic grain-boundary foam. Phys. Rev. B, 2009, 79:205206.
[101] Jones M I, McColl I R, Grant D M. Effect of substrate preparation and deposition conditions on the preferred orientation of TiN coatings deposited by RF reactive sputtering. Surface & Coatings Technology, 2000, 132:143-151.
[102] Ramgir N S, Hwang Y K, Mulla I S, et al. Effect of particle size and strain in nanocrystalline SnO2 according to doping concentration of ruthenium. Solid State Sciences, 2006, 8:359-362.
[103] Khranovskyy V, Minikayev R, Trushkin S, et al. Improvement of ZnO thin film properties by application of ZnO buffer layers. Journal of Crystal Growth, 2007, 308:93-98.
[104] Zhang J C, Zhao D G, Wang J F, et al. The influence of AlN buffer layer thickness on the properties of GaN epilayer. Journal of Crystal Growth, 2004, 268:24-29.
[105] Wang Q, Sun Q, Jena P, et al. Antiferromagnetic coupling driven by bond length contraction near the Ga1-xMnxN film surface. Phys. Rev. Lett., 2004, 93:155501.
[106] Kilic C, Zunger A. Origins of coexistence of conductivity and transparency in SnO2. Physical Review Letters, 2002, 88:095501.
[107] Gu Z B, Lu M H, Wang J, et al. Structure, optical, and magnetic properties of sputtered manganese and nitrogen-codoped ZnO films. Applied Physics Letters, 2006, 88:082111.
[108] Cao P, Zhao D X, Zhangb J Y, et al. N-doping-related room temperature ferromagnetism of electrodeposited ZnCoO films. Physica B: Condensed Matter, 2007, 392:255-258.
[109] Kittilstved K R, Norberg N S, Gamelin D R. Chemical manipulation of High-TC ferromagnetism in ZnO diluted magnetic semiconductors. Physical Review Letters, 2005, 94:147209.
[110] Xu X H, Qin X F, Jiang F X, et al. The dopant concentration and annealing temperature dependence of ferromagnetism in Co-doped ZnO thin films. Applied Surface Science, 2008, 254:4956-4960.
[111] Thomas D G. Interstitial zinc in zinc oxide. Journal of Physics and Chemistry of Solids, 1957, 3:229-237.
[112] Howard J M, Craciun V, Essary C, et al. Interfacial layer formation during high-temperature annealing of ZrO2 thin films on Si. Applied Physics Letters, 2002, 81:3431-3433.
[113] Sharma R K, Chan P C H, Tang Z A, et al. Sensitive, selective and stable tin dioxide thin-films for carbon monoxide and hydrogen sensing in integrated gas sensor array applications. Sensors And Actuators B-Chemical, 2001, 72:160-166.
[114] Schultz P J, Lynn K G. Interaction of positron beams with surfaces, thin-films, and interfaces. Reviews Of Modern Physics, 1988, 60:701-779.
[115] Veen A V, Schut H, Vries J D, et al. Analysis of positron profiling data by means of "VEPFIT". AIP Conf. Proc., 1991, 218:171-198.
[116] Uedono A, Koida T, Tsukazaki A, et al. Defects in ZnO thin films grown on ScAlMgO4 substrates probed by a monoenergetic positron beam. Journal Of Applied Physics, 2003, 93:2481-2485.
[117] MacManus-Driscoll J L, Khare N, Liu Y L, et al. Structural evidence for Zn intersititials in ferromagnetic Zn1-xCoxO films. Advanced Materials, 2007, 19:2925.
[118] Schwartz D A, Gamelin D R. Reversible 300 K ferromagnetic ordering in a diluted magnetic semiconductor. Advanced Materials, 2004, 16:2115.
[119] Batzill M, Morales E H, Diebold U. Influence of nitrogen doping on the defect formation and surface properties of TiO2 rutile and anatase. Phys. Rev. Lett., 2006, 96:026103.
[120] Pan S S, Shen Y D, Teng X M, et al. Substitutional nitrogen-doped tin oxide single crystalline submicrorod arrays: Vertical growth, band gap tuning and visible light-driven photocatalysis. Materials Research Bulletin, 2009, 44:2092-2098.
[121] Xu P, Mi L, Wang P N. Improved optical response for N-doped anatase TiO2 films prepared by pulsed laser deposition in N2/NH3/O2 mixture. Journal Of Crystal Growth, 2006, 289:433-439.
[122] Tong K Y, Jelenkovic E V, Liu W, et al. Nitridation of hafnium oxide by reactive sputtering. Microelectronic Engineering, 2006, 83:293-297.
[123] Park K C, Ma D Y, Kim K H. The physical properties of Al-doped zinc oxide films prepared by RF magnetron sputtering. Thin Solid Films, 1997, 305:201-209.
[124] Futsuhara M, Yoshioka K, Takai O. Optical properties of zinc oxynitride thin films. Thin Solid Films, 1998, 317:322-325.
[125] Pan S S, Zhang Y X, Teng X M, et al. Optical properties of nitrogen-doped SnO2 films: Effect of the electronegativity on refractive index and band gap. Journal Of Applied Physics, 2008, 103:093103.
[126] Liu X F, Sun Y, Yu R H. Role of oxygen vacancies in tuning magnetic properties of Co-doped SnO2 insulating films. J. Appl. Phys., 2007, 101:123907.
[127] Liu X F, Yu R H. Mediation of room temperature ferromagnetism in Co-doped SnO2 nanocrystalline films by structural defects. J. Appl. Phys., 2007, 102:083917.
[128] Bergqvist L, Eriksson O, Kudrnovsky J, et al. Magnetic percolation in diluted magnetic semiconductors. Physical Review Letters, 2004, 93:137202.
[129] Venkatesan M, Fitzgerald C B, Lunney J G, et al. Anisotropic ferromagnetism in substituted zinc oxide. Phys. Rev. Lett., 2004, 93:177206.
[130] Samanta K, Bhattacharya P, Katiyar R S, et al. Raman scattering studies in dilute magnetic semiconductor Zn1-xCoxO. Phys. Rev. B, 2006, 73:245213.
[131] Yang Z, Liu J L, Biasini M, et al. Electron concentration dependent magnetization and magnetic anisotropy in ZnO: Mn thin films. Appl. Phys. Lett., 2008, 92:042111.
[132] Liu X J, Song C, Yang P Y, et al. Substrate orientation-induced distinct ferromagnetic moment in Co:ZnO films. Applied Surface Science, 2008, 254:3167-3174.
[133] Dorneles L S, O'Mahony D, Fitzgerald C B, et al. Structural and compositional analysis of transition-metal-doped ZnO and GaN PLD thin films. Applied Surface Science, 2005, 248:406-410.
[134] Cheng G, Wu K, Zhao P T, et al. Controlled growth of oxygen-deficient tin oxide nanostructures via a solvothermal approach in mixed solvents and their optical properties. Nanotechnology, 2007, 18:355604.
[135] Wang Q, Sun Q, Chen G, et al. Vacancy-induced magnetism in ZnO thin films and nanowires. Phys. Rev. B, 2008, 77:205411.
[136] Liu C M, Zu X T, Wei Q M, et al. Fabrication and characterization of wire-like SnO2. Journal of Physics D-Applied Physics, 2006, 39:2494-2497.
[137] Luo S H, Fan J Y, Liu W L, et al. Synthesis and low-temperature photoluminescence properties of SnO2 nanowires and nanobelts. Nanotechnology, 2006, 17:1695-1699.
[138] Wang B, Yang Y H, Yang G W. Growth mechanisms of SnO2/Sn nanocables. Nanotechnology, 2006, 17:4682-4688.
[139] Elfimov I S, Yunoki S, Sawatzky G A. Possible path to a new class of ferromagnetic and half-metallic ferromagnetic materials. Phys. Rev. Lett., 2002, 89:216403.
[140] Monnier R, Delley B. Point defects, ferromagnetism, and transport in calcium hexaboride. Phys. Rev. Lett., 2001, 87:157204.
[141] Nomura K, Barrero C A, Sakuma J, et al. Room-temperature ferromagnetism of sol-gel-synthesized Sn1-x57FexO2-δpowders. Phys. Rev. B, 2007, 75:184411.
[142] Leite E R, Giraldi T R, Pontes F M, et al. Crystal growth in colloidal tin oxide nanocrystals induced by coalescence at room temperature. Appl. Phys. Lett., 2003, 83:1566-1568.
[143] Vayssieres L, Graetzel M. Highly ordered SnO2 nanorod arrays from controlled aqueous growth. Angew. Chem. Int. Edit, 2004, 43:3666-3670.
[144] Chen Y Q, Cui X F, Zhang K, et al. Bulk-quantity synthesis and self-catalytic VLS growth of SnO2 nanowires by lower-temperature evaporation. Chem. Phys. Lett., 2003, 369:16-20.
[145] Dai Z R, Pan Z W, Wang Z L. Novel nanostructures of functional oxides synthesized by thermal evaporation. Adv. Funct. Mater., 2003, 13:9-24.
[146] Wang B, Callahan M J, Xu C, et al. Hydrothermal growth and characterization of indium-doped-conducting ZnO crystals. J. Crystal. Growth, 2007, 304:73-79.
[147] Braybrook A L, Heywood B R, Jackson R A, et al. Parallel computational and experimental studies of the morphological modification of calcium carbonate by cobalt. J. Crystal. Growth, 2002, 243:336-344.
[148] [148].Porto S P S, Fleury P A, Damen T C. Raman Spectra of TiO2, MgF2, ZnF2, FeF2, and MnF2. Phys. Rev., 1967, 154:522-526.
[149] Abello L, Bochu B, Gaskov A, et al. Structural characterization of nanocrystalline SnO2 by X-ray and Raman spectroscopy. J. Solid. State Chem., 1998, 135:78-85.
[150] Harumoto T, Iqbal J, Liu X F, et al. Effects of hydroxyls on the structural and room temperature ferromagnetic properties of Co doped SnO2 nanoparticles. Appl. Phys. A-Mater., 2009, 97:211-215.
[151] Loridant S. Determination of the maximum vanadium oxide coverage on SnO2 with a high surface area by Raman spectroscopy. J. Phys. Chem. B, 2002, 106:13273-13279.
[152] Shek C H, Lin G M, Lai J K L. Effect of oxygen deficiency on the Raman spectra and hyperfine interactions of nanometer SnO2. Nanostructured Materials, 1999, 11:831-835.
[153] Geraldo V, Briois V, Scalvi L V A, et al. EXAFS investigation on Sb incorporation effects to electrical transport in SnO2 thin films deposited by sot-gel. J. Eur Ceram. Soc, 2007, 27:4265-4268.
[154] Chawla S, Jayanthi K, Kotnala R K. Room-temperature ferromagnetism in Li-doped p-type luminescent ZnO nanorods. Phys. Rev. B, 2009, 79:125204.
[155] Yang X L, Chen Z T, Wu J J, et al. Magnetic and magneto-transport properties of Ga1-xMnxN grown by MOCVD. Journal of Crystal Growth, 2007, 305:144-148.
[156] Zhang J, Skomski R, Sellmyer D J. Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO. J. Appl. Phys., 2005, 97:10d303.
[157] Han D S, Bae S Y, Seo H W, et al. Synthesis and magnetic properties of manganese-doped GaP nanowires. Journal of Physical Chemistry B, 2005, 109:9311-9316.
[158] Bouzerar G, Ziman T. Model for vacancy-induced d0 ferromagnetism in oxide compounds. Phys. Rev. Lett., 2006, 96:207602.
[159] Bogdanov K P, Dimitrov D T, Lutskaya O F, et al. Equilibrium of native point defects in tin dioxide. Semiconductors, 1998, 32:1033.
[160] Máca F, Kudrnovsky J, Drchal V, et al. Magnetism without magnetic impurities in oxides ZrO2 and TiO2. Philos. Mag., 2008, 88:2755.
[161] Huang L M, Rosa A L, Ahuja R. Ferromagnetism in Cu-doped ZnO from first-principles theory. Phys. Rev. B, 2006, 74:075206.
[2] Vonhelmolt R, Wecker J, Holzapfel B, et al. Giant negative magnetoresistance in perovskitelike La2/3Ba1/3MnOx ferromagnetic-films. Phys. Rev. Lett., 1993, 71:2331-2333.
[3] Moodera J S, Kinder L R, Wong T M, et al. Large magnetoresistance at room-temperature in ferromagnetic thin-film tunnel-junctions. Phys. Rev. Lett., 1995, 74:3273-3276.
[4] Schmidt G, Ferrand D, Molenkamp L W, et al. Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor. Phys. Rev. B, 2000, 62:R4790-R4793.
[5] Cooley B J, Clark T E, Liu B Z, et al. Growth of magneto-optically active (Zn,Mn)Se nanowires. Nano Letters, 2009, 9:3142-3146.
[6] Bacaksiz E, Tomakin M, Altunbas M, et al. Structural, optical and magnetic properties of Cd(1-x)CoxS thin films prepared by spray pyrolysis. Physica B-Condensed Matter, 2008, 403:3740-3745.
[7] Bouloudenine M, Viart N, Colis S, et al. Antiferromagnetism in bulk Zn1-xCoxO magnetic semiconductors prepared by the coprecipitation technique. Appl. Phys. Lett., 2005, 87:052501.
[8] Jayakumar O D, Sudakar C, Persson C, et al. 1D morphology stabilization and enhanced magnetic properties of Co:ZnO nanostructures on codoping with Li: A template-free synthesis. Crystal Growth & Design, 2009, 9:4450-4455.
[9] Macdonald A H, Schiffer P, Samarth N. Ferromagnetic semiconductors: Moving beyond (Ga,Mn)As. Nat. Mater., 2005, 4:195-202.
[10] Jungwirth T, Wang K Y, Masek J, et al. Prospects for high temperature ferromagnetism in (Ga,Mn)As semiconductors. Phys. Rev. B, 2005, 72:165204.
[11] Dehbaoui M, Benkhettou N, Benrekia R A. First principle calculation for structural properties and bowing parameter in Ga1-xMnxN materials. Mat. Sci. Semicon. Proc., 2008, 11:37-43.
[12] Bihler C, Gerstmann U, Hoeb M, et al. Manganese-hydrogen complexes in Ga1-xMnxN. Phys. Rev. B, 2009, 80:205205.
[13] Lussier A, Dvorak J, Idzerda Y U, et al. Comparative x-ray absorption spectroscopy study of Co-doped SnO2 and TiO2. J. Appl. Phys., 2004, 95:7190-7191.
[14] Hong N H, Sakai J, Prellier W, et al. Room temperature ferromagnetism in laser ablated transition-metal-doped TiO2 thin films on various types of substrates. Journal Of Physics D-Applied Physics, 2005, 38:816-821.
[15] Elamrani M, Lascaray J P, Diouri J. Fundamental Absorption Of Cd1-xMnxTe Crystals. Solid State Communications, 1983, 45:351-353.
[16] Diouri J, Lascaray J P, Elamrani M. Effect of the magnetic order on the optical-absorption edge in Cd1-xMnxTe. Phys. Rev. B, 1985, 31:7995-7999.
[17] Furdyna J K. Diluted Magnetic Semiconductors. J. Appl. Phys., 1988, 64:R29-R64.
[18] Ziese M, Thorntom M J. Spin electronics. Berlin: Springer, 2001.
[19]王学忠,陈辰嘉,王荣明,等. Cd1-xMnxTe的巨大法拉第旋转与激子跃迁.半导体学报, 1994, 15:333.
[20] Shinde S R, Ogale S B, Higgins J S, et al. Co-occurrence of superparamagnetism and anomalous Hall effect in highly reduced cobalt-doped rutile TiO2-δfilms. Phys. Rev. Lett., 2004, 92:166601.
[21] Xu Q Y, Hartmann L, Schmidt H, et al. Metal-insulator transition in Co-doped ZnO: Magnetotransport properties. Phys. Rev. B, 2006, 73:205342.
[22] Ohno H, Chiba D, Matsukura F, et al. Electric-field control of ferromagnetism. Nature, 2000, 408:944-946.
[23]王颖,湛永钟,许艳飞,等.稀磁半导体材料的研究进展及应用前景.材料导报, 2007, 21:20-23.
[24] Dietl T. Optical-properties of donor electrons in semimagnetic semiconductors. Journal of Magnetism and Magnetic Materials, 1983, 38:34-44.
[25] Furdyna J K. Electrical, optical, and magnetic-properties of Hg1-xMnxTe. Journal of Vacuum Science & Technology, 1982, 21:220-228.
[26] Ohno H, Shen A, Matsukura F, et al. (Ga,Mn)As: A new diluted magnetic semiconductor based on GaAs. Appl. Phys. Lett., 1996, 69:363-365.
[27] Ohno Y, Young D K, Beschoten B, et al. Electrical spin injection in a ferromagnetic semiconductor heterostructure. Nature, 1999, 402:790-792.
[28] Dietl T, Ohno H, Matsukura F, et al. Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science, 2000, 287:1019-1022.
[29] Sudakar C, Thakur J S, Lawes G, et al. Ferromagnetism induced by planar nanoscale CuO inclusions in Cu-doped ZnO thin films. Phys. Rev. B, 2007, 75:054423.
[30] Liu X J, Song C, Zeng F, et al. Strain-induced ferromagnetism enhancement in Co:ZnO films. J. Appl. Phys., 2008, 103:093911.
[31] Pan F, Song C, Liu X J, et al. Ferromagnetism and possible application in spintronics of transition-metal-doped ZnO films. Materials Science & Engineering R-Reports, 2008, 62:1-35.
[32] Krishnaiah G, Rao N M, Reddy B K, et al. EPR and magnetic properties of vapour phase grown Zn1-xCrxTe crystals. Physics Letters A, 2008, 372:6429-6433.
[33] Soundararajan D, Mangalaraj D, Nataraj D, et al. Ferromagnetism in Zn1-xCrxTe (x=0.05, 0.15) films grown on GaAs(100) substrate. Current Applied Physics, 2010, 10:771-775.
[34] Jiang F X, Xu X H, Zhang J, et al. Role of carrier and spin in tuning ferromagnetism in Mn and Cr-doped In2O3 thin films. Appl. Phys. Lett., 2010, 96:052503.
[35] Sudakar C, Dixit A, Kumar S, et al. Coexistence of anion and cation vacancy defects in vacuum-annealed In2O3 thin films. Scripta Materialia, 2010, 62:63-66.
[36] Higgins J S, Shinde S R, Ogale S B, et al. Hall effect in cobalt-doped TiO2-δ. Phys. Rev. B, 2004, 69:073201.
[37] Chen J, Rulis P, Ouyang L Z, et al. Vacancy-enhanced ferromagnetism in Fe-doped rutile TiO2. Phys. Rev. B, 2006, 74:235207.
[38] Lee H M, Kim S J, Shim I B, et al. Effects of Nb doping on the magnetism of anatase Fe-doped TiO2. Ieee Transactions on Magnetics, 2006, 42:2706-2708.
[39] Ueda K, Tabata H, Kawai T. Magnetic and electric properties of transition-metal-doped ZnO films. Appl. Phys. Lett., 2001, 79:988-990.
[40] Farley N R S, Edmonds K W, Freeman A A, et al. Magnetic properties of sol-gel-derived doped ZnO as a potential ferromagnetic semiconductor: A synchrotron-based. New Journal of Physics, 2008, 10:055012.
[41] Peleckis G, Wang X L, Dou S X. High temperature ferromagnetism in Ni-doped In2O3 and indium-tin oxide. Appl. Phys. Lett., 2006, 89:022501.
[42] Chambers S A, Droubay T, Wang C M, et al. Clusters and magnetism in epitaxial Co-doped TiO2 anatase. Appl. Phys. Lett., 2003, 82:1257-1259.
[43] Kim J H, Kim H, Kim D, et al. Magnetic properties of epitaxially grown semiconducting Zn1-xCoxO thin films by pulsed laser deposition. J. Appl. Phys., 2002, 92:6066-6071.
[44] Zener C. Interaction between the d-shells in the transition metals.2. ferromagnetic compounds of manganese with perovskite structure. Physical Review, 1951, 82:403-405.
[45] Sato K, Katayama-Yoshida H. Stabilization of ferromagnetic states by electron doping in Fe-, Co- or Ni-doped ZnO. Japanese Journal of Applied Physics Part 2-Letters, 2001, 40:L334-L336.
[46] Sato K, Katayama-Yoshida H. Material design for transparent ferromagnets with ZnO-based magnetic semiconductors. Japanese Journal of Applied Physics Part 2-Letters, 2000, 39:L555-L558.
[47] 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.
[48] Kasuya T. A theory of metallic ferromagnetism and antiferromagnetism on Zeners model. Progress of Theoretical Physics, 1956, 16:45-57.
[49] Yosida K. Magnetic properties of Cu-Mn alloys. Physical Review, 1957, 106:893-898.
[50] Ruderman M A, Kittel C. Indirect exchange coupling of nuclear magnetic moments by conducting electrons. Physical Review, 1954, 96:99-102.
[51] Liao L, Lu H B, Zhang L, et al. Effect of ferromagnetic properties in Al-doped Zn1-xCoxO nanowires synthesized by water-assistance reactive vapor deposition. J. Appl. Phys., 2007, 102:114307.
[52] Mounkachi O, Benyoussef A, El Kenz A, et al. Ab initio calculation of Zn0.8Mn0.2O1-yNy. Journal of Magnetism and Magnetic Materials, 2008, 320:2760-2765.
[53] Griffin K A, Pakhomov A B, Wang C M, et al. Intrinsic ferromagnetism in insulating cobalt doped anatase TiO2. Phys. Rev. Lett., 2005, 94:157204.
[54] Coey J M D, Venkatesan M, Fitzgerald C B. Donor impurity band exchange in dilute ferromagnetic oxides. Nat. Mater., 2005, 4:173-179.
[55] Venkatesan M, Fitzgerald C B, Coey J M D. Unexpected magnetism in a dielectric oxide. Nature, 2004, 430:630-630.
[56] Das Pemmaraju C, Sanvito S. Ferromagnetism driven by intrinsic point defects in HfO2. Phys. Rev. Lett., 2005, 94:217205.
[57] Bouzerar G, Ziman T. Model for vacancy-induced d(0) ferromagnetism in oxide compounds. Phys. Rev. Lett., 2006, 96:207602.
[58] Hong N H, Sakai J, Poirot N, et al. Room-temperature ferromagnetism observed in undoped semiconducting and insulating oxide thin films. Phys. Rev. B, 2006, 73:132404.
[59] Abraham D W, Frank M M, Guha S. Absence of magnetism in hafnium oxide films. Appl. Phys. Lett., 2005, 87:252502.
[60] Yu B L, Zhu C S, Gan F X. Exciton spectra of SnO2 nanocrystals with surficial dipole layer. Optical Materials, 1997, 7:15-20.
[61] Kimura H, Fukumura T, Kawasaki M, et al. Rutile-type oxide-diluted magnetic semiconductor: Mn-doped SnO2. Appl. Phys. Lett., 2002, 80:94-96.
[62] Ogale S B, Choudhary R J, Buban J P, et al. High temperature ferromagnetism with a giant magnetic moment in transparent Co-doped SnO2-δ. Phys. Rev. Lett., 2003, 91:077205.
[63] Gopinadhan K, Kashyap S C, Pandya D K, et al. Evidence of carrier mediated room temperature ferromagnetism in transparent semiconducting Sn1-xCoxO2-δthin films. Journal of Physics-Condensed Matter, 2008, 20:125208.
[64] Fitzgerald C B, Venkatesan M, Dorneles L S, et al. Magnetism in dilute magnetic oxide thin films based on SnO2. Phys. Rev. B, 2006, 74:115307.
[65] Hong N H, Sakai J. Ferromagnetic V-doped SnO2 thin films. Physica B-Condensed Matter, 2005, 358:265-268.
[66] Hong N H, Sakai J, Prellier W, et al. Transparent Cr-doped SnO2 thin films: Ferromagnetism beyond room temperature with a giant magnetic moment. Journal of Physics-Condensed Matter, 2005, 17:1697-1702.
[67] Coey J M D, Douvalis A P, Fitzgerald C B, et al. Ferromagnetism in Fe-doped SnO2 thin films. Appl. Phys. Lett., 2004, 84:1332-1334.
[68] Mathew X, Enriquez J P, Mejia-Garcia C, et al. Structural modifications of SnO2 due to the incorporation of Fe into the lattice. J. Appl. Phys., 2006, 100:073907.
[69] Archer P I, Radovanovic P V, Heald S M, et al. Low-temperature activation and deactivation of high-Curie-temperature ferromagnetism in a new diluted magnetic semiconductor: Ni2+-doped SnO2. Journal of the American Chemical Society, 2005, 127:14479-14487.
[70] 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.
[71] Gopinadhan K, Pandya D K, Kashyap S C, et al. Cobalt-substituted SnO2 thin films: A transparent ferromagnetic semiconductor. J. Appl. Phys., 2006, 99:126106.
[72] Bouaine A, Brihi N, Schmerber G, et al. Structural, optical, and magnetic properties of Co-doped SnO2 powders synthesized by the coprecipitation technique. J. Phys. Chem. C, 2007, 111:2924-2928.
[73] 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., 2004, 95:7390-7392.
[74] Hays J, Punnoose A, Baldner R, et al. Relationship between the structural and magnetic properties of Co-doped SnO2 nanoparticles. Phys. Rev. B, 2005, 72:075203.
[75] Wang W D, Wang Z J, Hong Y J, et al. Structure and magnetic properties of Cr/Fe-doped SnO2 thin films. J. Appl. Phys., 2006, 99:08m115.
[76] Sakuma J, Nomura K, Barrero C, et al. Mossbauer studies and magnetic properties of SnO2 doped with 57Fe. Thin Solid Films, 2007, 515:8653-8655.
[77] Rahman G, Garcia-Suarez V M, Hong S C. Vacancy-induced magnetism in SnO2: A density functional study. Phys. Rev. B, 2008, 78:184404.
[78] Zhou W, Liu L J, Wu P. Nonmagnetic impurities induced magnetism in SnO2. Journal of Magnetism and Magnetic Materials, 2009, 321:3356-3359.
[79]侯鹤岚.直流磁控溅射镀膜在玻璃涂层技术中的应用.真空, 2001:18-22.
[80]徐如人.无机合成化学.北京:北京高等教育出版社, 1991.
[81] Chen Z Q, Maekawa M, Kawasuso A, et al. Annealing process of ion-implantation-induced defects in ZnO: Chemical effect of the ion species. Journal of Applied Physics, 2006, 99:093507.
[82]王英华. X光衍射技术基础.北京:原子能出版社, 1993.
[83]黄新民.材料研究方法.哈尔滨:哈尔滨工业大学出版社, 2008.
[84]朱永法.纳米材料的表征与测试技术.北京:化学工业出版社, 2006.
[85]马礼敦,杨福家.同步辐射应用概论(第二版).上海:复旦大学出版社, 2001.
[86] Ankudinov A L, Ravel B, Rehr J J, et al. Real-space multiple-scattering calculation and interpretation of x-ray-absorption near-edge structure. Physical Review B, 1998, 58:7565-7576.
[87]郁伟中.正电子物理及其应用.北京:科学出版社, 2003.
[88]彭成晓.正电子对ZnO和GaN宽带隙半导体中缺陷的研究[博士学位论文].合肥:中国科技大学, 2006.
[89] Chen Z Q, Maekawa M, Yamamoto S, et al. Evolution of voids in Al+-implanted ZnO probed by a slow positron beam. Physical Review B, 2004, 69:035210.
[90]陈海英.精密磁强计的发展现状及应用.现代仪器, 2000:5-7.
[91]陈培榕,邓勃.现代仪器分析实验与技术.北京:清华大学出版社, 2001.
[92] Tuan A C, Bryan J D, Pakhomov A B, et al. Epitaxial growth and properties of cobalt-doped ZnO on alpha-Al2O3 single-crystal substrates. Phys. Rev. B, 2004, 70:054424.
[93] Pan S S, Ye C, Teng X M, et al. Preparation and characterization of nitrogen-incorporated SnO2 films. Applied Physics a-Materials Science & Processing, 2006, 85:21-24.
[94] Chambers S A, Heald S M, Droubay T. Local Co structure in epitaxial CoxTi1-xO2-x anatase. Phys. Rev. B, 2003, 67:100401.
[95] Hong N H, Sakai J, Huong N T, et al. Role of defects in tuning ferromagnetism in diluted magnetic oxide thin films. Phys. Rev. B, 2005, 72:045336.
[96] Matsumoto Y, Murakami M, Shono T, et al. Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide. Science, 2001, 291:854-856.
[97] Song C, Geng K W, Zeng F, et al. Giant magnetic moment in an anomalous ferromagnetic insulator: Co-doped ZnO. Phys. Rev. B, 2006, 73:024405.
[98] Kim J Y, Park J H, Park B G, et al. Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films. Phys. Rev. Lett., 2003, 90:017401.
[99] Huang C L, Wang J J, Hsu C H. Influence of deposition pressure and rf power on the structure and electrical properties of Zr0.8Sn0.2TiO4 thin films prepared by rf magnetron sputtering. Journal of Vacuum Science & Technology B, 2007, 25:299-305.
[100] Straumal B B, Mazilkin A A, Protasova S G, et al. Magnetization study of nanograined pure and Mn-doped ZnO films: Formation of a ferromagnetic grain-boundary foam. Phys. Rev. B, 2009, 79:205206.
[101] Jones M I, McColl I R, Grant D M. Effect of substrate preparation and deposition conditions on the preferred orientation of TiN coatings deposited by RF reactive sputtering. Surface & Coatings Technology, 2000, 132:143-151.
[102] Ramgir N S, Hwang Y K, Mulla I S, et al. Effect of particle size and strain in nanocrystalline SnO2 according to doping concentration of ruthenium. Solid State Sciences, 2006, 8:359-362.
[103] Khranovskyy V, Minikayev R, Trushkin S, et al. Improvement of ZnO thin film properties by application of ZnO buffer layers. Journal of Crystal Growth, 2007, 308:93-98.
[104] Zhang J C, Zhao D G, Wang J F, et al. The influence of AlN buffer layer thickness on the properties of GaN epilayer. Journal of Crystal Growth, 2004, 268:24-29.
[105] Wang Q, Sun Q, Jena P, et al. Antiferromagnetic coupling driven by bond length contraction near the Ga1-xMnxN film surface. Phys. Rev. Lett., 2004, 93:155501.
[106] Kilic C, Zunger A. Origins of coexistence of conductivity and transparency in SnO2. Physical Review Letters, 2002, 88:095501.
[107] Gu Z B, Lu M H, Wang J, et al. Structure, optical, and magnetic properties of sputtered manganese and nitrogen-codoped ZnO films. Applied Physics Letters, 2006, 88:082111.
[108] Cao P, Zhao D X, Zhangb J Y, et al. N-doping-related room temperature ferromagnetism of electrodeposited ZnCoO films. Physica B: Condensed Matter, 2007, 392:255-258.
[109] Kittilstved K R, Norberg N S, Gamelin D R. Chemical manipulation of High-TC ferromagnetism in ZnO diluted magnetic semiconductors. Physical Review Letters, 2005, 94:147209.
[110] Xu X H, Qin X F, Jiang F X, et al. The dopant concentration and annealing temperature dependence of ferromagnetism in Co-doped ZnO thin films. Applied Surface Science, 2008, 254:4956-4960.
[111] Thomas D G. Interstitial zinc in zinc oxide. Journal of Physics and Chemistry of Solids, 1957, 3:229-237.
[112] Howard J M, Craciun V, Essary C, et al. Interfacial layer formation during high-temperature annealing of ZrO2 thin films on Si. Applied Physics Letters, 2002, 81:3431-3433.
[113] Sharma R K, Chan P C H, Tang Z A, et al. Sensitive, selective and stable tin dioxide thin-films for carbon monoxide and hydrogen sensing in integrated gas sensor array applications. Sensors And Actuators B-Chemical, 2001, 72:160-166.
[114] Schultz P J, Lynn K G. Interaction of positron beams with surfaces, thin-films, and interfaces. Reviews Of Modern Physics, 1988, 60:701-779.
[115] Veen A V, Schut H, Vries J D, et al. Analysis of positron profiling data by means of "VEPFIT". AIP Conf. Proc., 1991, 218:171-198.
[116] Uedono A, Koida T, Tsukazaki A, et al. Defects in ZnO thin films grown on ScAlMgO4 substrates probed by a monoenergetic positron beam. Journal Of Applied Physics, 2003, 93:2481-2485.
[117] MacManus-Driscoll J L, Khare N, Liu Y L, et al. Structural evidence for Zn intersititials in ferromagnetic Zn1-xCoxO films. Advanced Materials, 2007, 19:2925.
[118] Schwartz D A, Gamelin D R. Reversible 300 K ferromagnetic ordering in a diluted magnetic semiconductor. Advanced Materials, 2004, 16:2115.
[119] Batzill M, Morales E H, Diebold U. Influence of nitrogen doping on the defect formation and surface properties of TiO2 rutile and anatase. Phys. Rev. Lett., 2006, 96:026103.
[120] Pan S S, Shen Y D, Teng X M, et al. Substitutional nitrogen-doped tin oxide single crystalline submicrorod arrays: Vertical growth, band gap tuning and visible light-driven photocatalysis. Materials Research Bulletin, 2009, 44:2092-2098.
[121] Xu P, Mi L, Wang P N. Improved optical response for N-doped anatase TiO2 films prepared by pulsed laser deposition in N2/NH3/O2 mixture. Journal Of Crystal Growth, 2006, 289:433-439.
[122] Tong K Y, Jelenkovic E V, Liu W, et al. Nitridation of hafnium oxide by reactive sputtering. Microelectronic Engineering, 2006, 83:293-297.
[123] Park K C, Ma D Y, Kim K H. The physical properties of Al-doped zinc oxide films prepared by RF magnetron sputtering. Thin Solid Films, 1997, 305:201-209.
[124] Futsuhara M, Yoshioka K, Takai O. Optical properties of zinc oxynitride thin films. Thin Solid Films, 1998, 317:322-325.
[125] Pan S S, Zhang Y X, Teng X M, et al. Optical properties of nitrogen-doped SnO2 films: Effect of the electronegativity on refractive index and band gap. Journal Of Applied Physics, 2008, 103:093103.
[126] Liu X F, Sun Y, Yu R H. Role of oxygen vacancies in tuning magnetic properties of Co-doped SnO2 insulating films. J. Appl. Phys., 2007, 101:123907.
[127] Liu X F, Yu R H. Mediation of room temperature ferromagnetism in Co-doped SnO2 nanocrystalline films by structural defects. J. Appl. Phys., 2007, 102:083917.
[128] Bergqvist L, Eriksson O, Kudrnovsky J, et al. Magnetic percolation in diluted magnetic semiconductors. Physical Review Letters, 2004, 93:137202.
[129] Venkatesan M, Fitzgerald C B, Lunney J G, et al. Anisotropic ferromagnetism in substituted zinc oxide. Phys. Rev. Lett., 2004, 93:177206.
[130] Samanta K, Bhattacharya P, Katiyar R S, et al. Raman scattering studies in dilute magnetic semiconductor Zn1-xCoxO. Phys. Rev. B, 2006, 73:245213.
[131] Yang Z, Liu J L, Biasini M, et al. Electron concentration dependent magnetization and magnetic anisotropy in ZnO: Mn thin films. Appl. Phys. Lett., 2008, 92:042111.
[132] Liu X J, Song C, Yang P Y, et al. Substrate orientation-induced distinct ferromagnetic moment in Co:ZnO films. Applied Surface Science, 2008, 254:3167-3174.
[133] Dorneles L S, O'Mahony D, Fitzgerald C B, et al. Structural and compositional analysis of transition-metal-doped ZnO and GaN PLD thin films. Applied Surface Science, 2005, 248:406-410.
[134] Cheng G, Wu K, Zhao P T, et al. Controlled growth of oxygen-deficient tin oxide nanostructures via a solvothermal approach in mixed solvents and their optical properties. Nanotechnology, 2007, 18:355604.
[135] Wang Q, Sun Q, Chen G, et al. Vacancy-induced magnetism in ZnO thin films and nanowires. Phys. Rev. B, 2008, 77:205411.
[136] Liu C M, Zu X T, Wei Q M, et al. Fabrication and characterization of wire-like SnO2. Journal of Physics D-Applied Physics, 2006, 39:2494-2497.
[137] Luo S H, Fan J Y, Liu W L, et al. Synthesis and low-temperature photoluminescence properties of SnO2 nanowires and nanobelts. Nanotechnology, 2006, 17:1695-1699.
[138] Wang B, Yang Y H, Yang G W. Growth mechanisms of SnO2/Sn nanocables. Nanotechnology, 2006, 17:4682-4688.
[139] Elfimov I S, Yunoki S, Sawatzky G A. Possible path to a new class of ferromagnetic and half-metallic ferromagnetic materials. Phys. Rev. Lett., 2002, 89:216403.
[140] Monnier R, Delley B. Point defects, ferromagnetism, and transport in calcium hexaboride. Phys. Rev. Lett., 2001, 87:157204.
[141] Nomura K, Barrero C A, Sakuma J, et al. Room-temperature ferromagnetism of sol-gel-synthesized Sn1-x57FexO2-δpowders. Phys. Rev. B, 2007, 75:184411.
[142] Leite E R, Giraldi T R, Pontes F M, et al. Crystal growth in colloidal tin oxide nanocrystals induced by coalescence at room temperature. Appl. Phys. Lett., 2003, 83:1566-1568.
[143] Vayssieres L, Graetzel M. Highly ordered SnO2 nanorod arrays from controlled aqueous growth. Angew. Chem. Int. Edit, 2004, 43:3666-3670.
[144] Chen Y Q, Cui X F, Zhang K, et al. Bulk-quantity synthesis and self-catalytic VLS growth of SnO2 nanowires by lower-temperature evaporation. Chem. Phys. Lett., 2003, 369:16-20.
[145] Dai Z R, Pan Z W, Wang Z L. Novel nanostructures of functional oxides synthesized by thermal evaporation. Adv. Funct. Mater., 2003, 13:9-24.
[146] Wang B, Callahan M J, Xu C, et al. Hydrothermal growth and characterization of indium-doped-conducting ZnO crystals. J. Crystal. Growth, 2007, 304:73-79.
[147] Braybrook A L, Heywood B R, Jackson R A, et al. Parallel computational and experimental studies of the morphological modification of calcium carbonate by cobalt. J. Crystal. Growth, 2002, 243:336-344.
[148] [148].Porto S P S, Fleury P A, Damen T C. Raman Spectra of TiO2, MgF2, ZnF2, FeF2, and MnF2. Phys. Rev., 1967, 154:522-526.
[149] Abello L, Bochu B, Gaskov A, et al. Structural characterization of nanocrystalline SnO2 by X-ray and Raman spectroscopy. J. Solid. State Chem., 1998, 135:78-85.
[150] Harumoto T, Iqbal J, Liu X F, et al. Effects of hydroxyls on the structural and room temperature ferromagnetic properties of Co doped SnO2 nanoparticles. Appl. Phys. A-Mater., 2009, 97:211-215.
[151] Loridant S. Determination of the maximum vanadium oxide coverage on SnO2 with a high surface area by Raman spectroscopy. J. Phys. Chem. B, 2002, 106:13273-13279.
[152] Shek C H, Lin G M, Lai J K L. Effect of oxygen deficiency on the Raman spectra and hyperfine interactions of nanometer SnO2. Nanostructured Materials, 1999, 11:831-835.
[153] Geraldo V, Briois V, Scalvi L V A, et al. EXAFS investigation on Sb incorporation effects to electrical transport in SnO2 thin films deposited by sot-gel. J. Eur Ceram. Soc, 2007, 27:4265-4268.
[154] Chawla S, Jayanthi K, Kotnala R K. Room-temperature ferromagnetism in Li-doped p-type luminescent ZnO nanorods. Phys. Rev. B, 2009, 79:125204.
[155] Yang X L, Chen Z T, Wu J J, et al. Magnetic and magneto-transport properties of Ga1-xMnxN grown by MOCVD. Journal of Crystal Growth, 2007, 305:144-148.
[156] Zhang J, Skomski R, Sellmyer D J. Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO. J. Appl. Phys., 2005, 97:10d303.
[157] Han D S, Bae S Y, Seo H W, et al. Synthesis and magnetic properties of manganese-doped GaP nanowires. Journal of Physical Chemistry B, 2005, 109:9311-9316.
[158] Bouzerar G, Ziman T. Model for vacancy-induced d0 ferromagnetism in oxide compounds. Phys. Rev. Lett., 2006, 96:207602.
[159] Bogdanov K P, Dimitrov D T, Lutskaya O F, et al. Equilibrium of native point defects in tin dioxide. Semiconductors, 1998, 32:1033.
[160] Máca F, Kudrnovsky J, Drchal V, et al. Magnetism without magnetic impurities in oxides ZrO2 and TiO2. Philos. Mag., 2008, 88:2755.
[161] Huang L M, Rosa A L, Ahuja R. Ferromagnetism in Cu-doped ZnO from first-principles theory. Phys. Rev. B, 2006, 74:075206.
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