FeSe超导体烧结成相过程及反应机理
摘要
铁基超导中的FeSe超导材料由于结构简单、制备容易，且不含有毒元素，成为研究铁基超导机理的最佳体系，同时也为研究超导机制提供了新的思路。目前人们对FeSe的研究主要集中于提高超导性能，在成相过程及机理方面比较欠缺。本实验通过差热分析、扫描电镜等分析手段对未掺杂FeSe和Te掺杂FeSe的成相过程、生长方式进行研究并利用多重速率扫描法中的FWO法对初始阶段的反应机理进行动力学分析。所得主要结论如下：
在球磨预处理过程中，Fe-Se粉末中大部分Se会非晶化。在随后的烧结过程中，Fe-Se混合粉末先后经历FeSe_2，Fe_3Se_4和α-FeSe等中间相后最终生成β-FeSe超导相。β-FeSe超导相的生长方式为二维形核生长机制下的层状生长。Fe-Se混合粉末初始反应过程的最概然机理函数为1/2 ( ) 2[ ln(G 1)]，表明该反应的动力学模型为随机成核和随后生长，且每个颗粒上只有一个核心。计算得到激活能和指前因子均随转变分数的升高而降低。
对Fe-Se-Te混合粉末球磨处理后，大部分Se进入Te的晶格中。Fe-Se-Te混合粉末在烧结过程中，除了形成FeSe_2，Fe_3Se_4等中间相，还会生成FeTe1.45中间相，最终生成的FeSe0.5Te0.5超导相的生长方式同样为二维形核生长机制下的层状生长。对比发现，Te掺杂能够提高烧结样品中四方晶体超导相的比例。Te掺杂后Fe-Se初始阶段的反应机理变为二维的相边界反应，对应的机理函数积分表达式为1/2 G() 2[1(1) ]。Te掺杂后激活能和指前因子均随转变分数增长而增大，其值均高于Fe-Se体系。
The FeSe superconductor, one of the iron-based superconductors, is the best candidate to study the mechanism of iron-based superconductor due to its simple structure, easy preparation and non-toxic, providing a new way of studying the mechanism of superconductivity as well. At present, the researches on FeSe mainly focus on improving superconductivity. However, studies on phase formation and reaction mechanism are rarely reported. In this study, phase formation process, as well as growth mode of the initial stages for undoped and Te doped FeSe are investigated by means of thermal analysis, scanning electron microscopy and other analytical tools, and corresponding reaction mechanism is analyzed by modified FWO method, which is one of the multiple rate scanning methods. The main conclusions are as follows:
The majority of Se becomes amorphous during the ball milling process of Fe-Se mixed powders. In the sintering process,β-FeSe superconducting phase lastly forms after the successively formation of FeSe_2, Fe_3Se_4, andα-FeSe. The growth mode ofβ-FeSe phase follows two-dimensional nucleation growth mechanism, thus exhibits layered grains.
The most fitting function for initial reaction of Fe-Se mixed powders is G ( ) 2[ ln(1 )]1/2, indicating a random nucleation followed by a subsequent growth, and each particle having only one core. The activation energy and pre-exponential factor both decrease with the increasing fractionα.
Substitution of Se for Te into lattice could be observed after the ball milling process of Fe-Se-Te mixed powders. In the sintering process of Fe-Se-Te mixed powders, besides FeSe_2 and Fe_3Se_4, FeTe1.45 forms as a new intermediate phase, while the superconductive FeSe0.5Te0.5 phase, which is the final product, shows layered growth mode of two-dimensional nucleation and growth. The proportion of tetragonal phase is increased resulted from Te doping.
The reaction mechanism for initial reaction of Te doped FeSe converts to two-dimensional phase boundary reaction, and the function is G ( ) 2[1 (1 )1 /2]. The activation energy and pre-exponential factor both increase with the increasing fractionαafter Te doping, and the values are all higher than that of FeSe system.
在球磨预处理过程中，Fe-Se粉末中大部分Se会非晶化。在随后的烧结过程中，Fe-Se混合粉末先后经历FeSe_2，Fe_3Se_4和α-FeSe等中间相后最终生成β-FeSe超导相。β-FeSe超导相的生长方式为二维形核生长机制下的层状生长。Fe-Se混合粉末初始反应过程的最概然机理函数为1/2 ( ) 2[ ln(G 1)]，表明该反应的动力学模型为随机成核和随后生长，且每个颗粒上只有一个核心。计算得到激活能和指前因子均随转变分数的升高而降低。
对Fe-Se-Te混合粉末球磨处理后，大部分Se进入Te的晶格中。Fe-Se-Te混合粉末在烧结过程中，除了形成FeSe_2，Fe_3Se_4等中间相，还会生成FeTe1.45中间相，最终生成的FeSe0.5Te0.5超导相的生长方式同样为二维形核生长机制下的层状生长。对比发现，Te掺杂能够提高烧结样品中四方晶体超导相的比例。Te掺杂后Fe-Se初始阶段的反应机理变为二维的相边界反应，对应的机理函数积分表达式为1/2 G() 2[1(1) ]。Te掺杂后激活能和指前因子均随转变分数增长而增大，其值均高于Fe-Se体系。
The FeSe superconductor, one of the iron-based superconductors, is the best candidate to study the mechanism of iron-based superconductor due to its simple structure, easy preparation and non-toxic, providing a new way of studying the mechanism of superconductivity as well. At present, the researches on FeSe mainly focus on improving superconductivity. However, studies on phase formation and reaction mechanism are rarely reported. In this study, phase formation process, as well as growth mode of the initial stages for undoped and Te doped FeSe are investigated by means of thermal analysis, scanning electron microscopy and other analytical tools, and corresponding reaction mechanism is analyzed by modified FWO method, which is one of the multiple rate scanning methods. The main conclusions are as follows:
The majority of Se becomes amorphous during the ball milling process of Fe-Se mixed powders. In the sintering process,β-FeSe superconducting phase lastly forms after the successively formation of FeSe_2, Fe_3Se_4, andα-FeSe. The growth mode ofβ-FeSe phase follows two-dimensional nucleation growth mechanism, thus exhibits layered grains.
The most fitting function for initial reaction of Fe-Se mixed powders is G ( ) 2[ ln(1 )]1/2, indicating a random nucleation followed by a subsequent growth, and each particle having only one core. The activation energy and pre-exponential factor both decrease with the increasing fractionα.
Substitution of Se for Te into lattice could be observed after the ball milling process of Fe-Se-Te mixed powders. In the sintering process of Fe-Se-Te mixed powders, besides FeSe_2 and Fe_3Se_4, FeTe1.45 forms as a new intermediate phase, while the superconductive FeSe0.5Te0.5 phase, which is the final product, shows layered growth mode of two-dimensional nucleation and growth. The proportion of tetragonal phase is increased resulted from Te doping.
The reaction mechanism for initial reaction of Te doped FeSe converts to two-dimensional phase boundary reaction, and the function is G ( ) 2[1 (1 )1 /2]. The activation energy and pre-exponential factor both increase with the increasing fractionαafter Te doping, and the values are all higher than that of FeSe system.
引文
[1] H.K. Onnes, The resistance of pure mercury at helium temperatures, Commun Phys Lab University Leiden, 1911, (12): 120~122
[2]章立源,超越自由,神奇的超导体,北京:科学出版社, 2005, 7: 16~27
[3]韩汝珊,吴勇,超导物理基础,北京:北京大学出版社, 1997: 4~12
[4]林良真,张金龙,李传义等,超导电性及其应用,北京:北京工业大学出版社, 1998: 1~18
[5]刘永长,马宗青, MgB2超导体的成相与掺杂机理,北京:科学出版社, 2009: 1~5
[6] J. Bardeen, L.N. Copper, J.R. Schrieffer, Theory of Superconductivity, Phys.Rev., 1957, (108): 1175~1208
[7] J.R. Gavaler, Superconductivity in Nb-Ge Films above 22K, Appl.Phys.Lett., 1957,( 23): 480~483
[8] J.G. Bednorz, K.A. Muller, Possible high Tc superconductivity in the Ba-La-Cu-O system, Z. Physik, 1986, (64): 189~193
[9] C. Kittel, Introduction to Solid State Physics, 6th ed, 1986: 321
[10]杨遇春,稀土元素在高温超导材料中的应用,稀有金属材料与工程, 2000, 29(2): 78~81
[11]赵忠贤,陈立泉,崔长庚等,近期超导电性研发亮点,科学通报, 1987, (32): 107.
[12] M.K. Wu, J.R. Ashburn, C.J. Torng, et al., Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure, Phys.Rev.Lett., 1987, (58): 908~910
[13] Z. Tarnawski, N.T.H. Kim-Ngan, X.Z. Wang, et al., Specific heat of RBa2Cu3O7-x and RBaSrCu3O7-x compounds (R = Sm, Dy, Er), Acta Physica Polonica A, 1998, 93(3): 513~522
[14] L.P. Kozeeva, M.Y. Kameneva, A.N. Lavrov, et al., Growth, morphology, and superconducting properties of RBa2Cu3O7-x (R = Tm, Lu) single crystals, Inorganic Materials, 1998, 34(10): 1057~1064
[15] J.A. McAllister, J.P. Attfield, Cation disorder effects in RBa2Cu3O7-x superconductors, International Journal of Inorganic Materials, 1999, 1(34): 269~271
[16] S.A. Antony, K.S. Nagaraja, S. Sahasranaman, et al., Complete chemical control of stoichiometry of materials related to high Tc ceramics RBa2Cu3O7-x (R = rare earth), Physica C-Superconductivity and Its Applications, 1999, 323(34): 115~121
[17] E. Gmelin, S.M. Sarge, Temperature, heat and heat flow rate calibration of differential scanning calorimeters, Thermochimica Acta, 2000, 347(12): 9~13
[18] V.F. Masterov, F.S. Nasredinov, N.P. Seregin, et al., Charge states of atoms in the lattices of the high-temperature superconductors Tl2Ba2Can-1CunO2n+4 and Bi2Sr2Can-1CunO2n+4, Journal of Experimental and Theoretical Physics, 1998, 87(3): 588~593
[19] L. Jansen, R. Block, Effect of iodine intercalation on superconductivity in the high- Tc series Bi2Sr2CaN-1CuNO2N+4+delta, N=1-3, and in the yttrium doped N=2 compound. A quantitative analysis on the basis of indirect exchange pairing, Physica A, 2000, 277(12): 183~203
[20] H. Maeda, M. Fukitomi,et al., A new high- Tc oxide superconductor without a rare earth element, App.Phys., 1988, 27(2): 209~210
[21] T. Sato, H. Matsui, S. Nishina, et al., Low energy excitation and scaling in Bi2Sr2Can-1CunO2n+4 (n=1-3): Angle-resolved photoemission spectroscopy, Physical Review Letters, 2002, 89(6): 067005
[22] Z.Z. Sheng, A.M. Hermann, Bulk superconductivity at 120 K in the Ti–Ca/Ba–Cu–O system, Nature, 1988, (332): 138~139
[23] D. Sedmidubsky, J. Leitner, K. Knizek, et al., Phase relations in Hg-Ba-Ca-Cu-O system, Physica C-Superconductivity and Its Applications, 2000, (341): 509~510
[24] C.W. Chu, Evidence for novel polaronic Fermi-liquid in doped oxides, Physica C-Superconductivity and Its Applications, 2000, (25): 341~346
[25]张裕恒,超导物理,合肥:中国科学技术大学出版社, 2009, 1~28
[26] W. Meissner, R. Ochsenfeld, Einneuer effect bei eintrit der supraleifahigheit, NatureWissenschaften, 1933, (21): 787
[27] C.A. Reynolds, B. Serin, W.H. Wright, et al., Superconductivity of isotopes of Mercury, Phys. Rev., 1950, (78): 487
[28] E. Maxwell, Isotope effect in superconductivity of Mercury, Phys. Rev., 1950, (78): 477
[29] Y. Kamihara, H. Hiramatsu, M. Hirano, et al., Iron-based layered superconductor: LaOFeP, Journal of the American Chemical Society, 2006, 128(31): 10012~10013
[30] Y. Kamihara, T. Watanabe, M. Hirano, et al., Iron-based layered superconductor La[O1-xFx]FeAs (x=0.05-0.12) with Tc =26 K, Journal of the American Chemical Society, 2008, 130(11): 3296
[31]马廷灿,万勇,姜山,铁基超导材料制备研究进展,科学通报, 2009, 54(5): 557~568
[32] I.R. Shein, A.L. Ivanovskii, Band structure of SrFeAsF and CaFeAsF-the base phases of a new group of oxygen-free FeAs superconductors, Jetp Letters, 2008, 88(10): 683~687
[33] P. Cheng, B. Shen, G. Mu, et al., High- Tc superconductivity induced by doping rare-earth elements into CaFeAsF, Epl, 2009, 85(6): 67003
[34] X.Z. Jin, T. Watanabe, K. Takase, et al., Electrical and magnetic properties of La deficient superconductor La1-xOFeP, Journal of Alloys and Compounds, 2009, 488(1): 14~16
[35] H. Takahashi, K. Igawa, K. Arii, et al., Superconductivity at 43 K in an iron-based layered compound LaO1-xFxFeAs, Nature, 2008, 453(7193): 376~378
[36] Z.A. Ren, G.C. Che, X.L. Dong, et al., Superconductivity and phase diagram in iron-based arsenic-oxides ReFeAsO1-delta (Re = rare-earth metal) without fluorine doping, Epl, 2008, 83(1): 17002
[37] Z. Wei, H.O. Li, W.L. Hong, et al., Superconductivity at 57.3 K in La-doped iron-based layered compound Sm0.95La0.05O0.85F0.15FeAs, Journal of Superconductivity and Novel Magnetism, 2008, 21(4): 213~215
[38] M. Rotter, M. Tegel, D. Johrendt, et al., Spin-density-wave anomaly at 140 K in the ternary iron arsenide BaFe2As2, Physical Review B, 2008, 78(2): 4021
[39] M. Rotter, M. Pangerl, M. Tegel, et al., Superconductivity and crystal structures of (Ba1-xKx)Fe2AS2 (x=0-1), Angewandte Chemie-International Edition, 2008, 47(41): 7949~7952
[40] Z. Li, J.S. Tse, C.Q. Jin, Bonding in the "111" Type Ferropnictide Superconductor LiFeAs, Journal of Superconductivity and Novel Magnetism, 2010, 23(5): 579~581
[41] D.R. Parker, M.J. Pitcher, P.J. Baker, et al., Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs, Chemical Communications, 2009, (16): 2189~2191
[42] X.C. Wang, Q.Q. Liu, Y.X. Lv, et al., The superconductivity at 18 K in LiFeAs system, Solid State Communications, 2008, 148(12): 538~540
[43] K.W. Yeh, T.W. Huang, Y.L. Huang, et al., Tellurium substitution effect on superconductivity of the alpha-phase iron selenide, Epl, 2008, 84(3): 37002
[44] D.J. Gawryluk, J. Fink-Finowicki, A. Wisniewski, et al., Structure and Superconductivity of FeSe1-x and FeTe1-ySey Crystals: Dependence on the Synthesis Methods, Starting Composition, and Growth Conditions, Acta Physica Polonica A, 2010, 118(2): 331~335
[45] F.C. Hsu, J.Y. Luo, K.W. Yeh, et al., Superconductivity in the PbO-type structure alpha-FeSe, Proceedings of the National Academy of Sciences of the United States of America, 2008, 105(38): 14262~14264
[46] C.L. Song, Y.L. Wang, P. Cheng, et al., Direct Observation of Nodes and Twofold Symmetry in FeSe Superconductor, Science, 2011, 332(6036): 1410~1413
[47] T.M. McQueen, Q. Huang, V. Ksenofontov, et al., Extreme sensitivity of superconductivity to stoichiometry in Fe1+deltaSe, Physical Review B, 2009, 79(1): 014522
[48] A.J. Williams, T.M. McQueen, R.J. Cava, The stoichiometry of FeSe, Solid State Communications, 2009, 149(37-38): 1507~1509
[49] E. Pomjakushina, K. Conder, V. Pomjakushin, et al., Synthesis, crystal structure, and chemical stability of the superconductor FeSe1-x, Physical Review B, 2009, 80(2): 024517
[50] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Substitution Effects on FeSe Superconductor, Journal of the Physical Society of Japan, 2009, 78(7): 07412
[51] R.W. Gomez, V. Marquina, J.L. Perez-Mazariego, et al., Effects of Substituting Se with Te in the FeSe Compound: Structural, Magnetization and Mossbauer Studies, Journal of Superconductivity and Novel Magnetism, 2010, 23(4): 551~557
[52] K.W. Yeh, H.C. Hsu, T.W. Huang, et al., Se and Te Doping Study of the FeSe Superconductors, Journal of the Physical Society of Japan, 2008, (77): 19~22
[53] T.W. Huang, T.K. Chen, K.W. Yeh, et al., Doping-driven structural phase transition and loss of superconductivity in MxFe1-xSedelta (M=Mn, Cu), Physical Review B, 2010, 82(10):104502
[54] A.K. Yadav, A.D. Thakur, C.V. Tomy, Enhanced superconducting properties in FeCrxSe, Solid State Communications, 2011, 151(7): 557~560
[55] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Superconductivity in S-substituted FeTe, Applied Physics Letters, 2009, 94(1): 3058720
[56] M.K. Wu, K.W. Yeh, H.C. Hsu, et al., The development of the superconducting tetragonal PbO-type FeSe and related compounds, Physica Status Solidi B-Basic Solid State Physics, 2010, 247(3): 500~505
[57] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Superconductivity at 27 K in tetragonal FeSe under high pressure, Applied Physics Letters, 2008, 93(15): 152505
[58] S.S. Naghavi, S. Chadov, C. Felser, The role of correlations in the high-pressure phase of FeSe, Journal of Physics-Condensed Matter, 2011, 23(20): 205601
[59] L.M. Schoop, S.A. Medvedev, V. Ksenofontov, et al., Pressure-restored superconductivity in Cu-substituted FeSe, Physical Review B, 2011, 84(17): 174505
[60] R.S. Kumar, Y. Zhang, S. Sinogeikin, et al., Crystal and Electronic Structure of FeSe at High Pressure and Low Temperature, Journal of Physical Chemistry B, 2010, 114(39): 12597~12606
[61] A. Subedi, L.J. Zhang, D.J. Singh, et al., Density functional study of FeS, FeSe, and FeTe: Electronic structure, magnetism, phonons, and superconductivity, Physical Review B, 2008, 78(13): 134514
[62] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., FeTe as a candidate material for new iron-based superconductor, Physica C-Superconductivity and Its Applications, 2009, 469(20): 1027~1029
[63] G. Tsoi, A.K. Stemshorn, Y.K. Vohra, et al., High pressure superconductivity in iron-based layered compounds studied using designer diamonds, Journal of Physics-Condensed Matter, 2009, 21(23): 232201
[64] Y.P. Sun, S.B. Zhang, X.D. Zhu, et al., Superconductivity of FeSe0.89 crystal with hexagonal and tetragonal structures, Superconductor Science & Technology, 2009, 22(7): 075016
[65] B.H. Mok, S.M. Rao, M.C. Ling, et al., Growth and Investigation of Crystals of the New Superconductor alpha-FeSe from KCl Solutions, Crystal Growth & Design, 2009, 9(7): 3260~3264
[66] Z.L. Xiao, U. Patel, J. Hua, et al., Growth and superconductivity of FeSex crystals, Applied Physics Letters, 2009, 94(8): 082508
[67] K.W. Yeh, C.T. Ke, T.W. Huang, et al., Superconducting FeSe1-xTex Single Crystals Grown by Optical Zone-Melting Technique, Crystal Growth & Design, 2009, 9(11): 4847~4851
[68] O. Tkachenko, A. Morawski, A. Zaleski, et al., Synthesis, Crystal Growth and Epitaxial Layers Growth of FeSe0,88 Superconductor and Other Poison Materials by Use of High Gas Pressure Trap System, Journal of Superconductivity and Novel Magnetism, 2009, 22(6): 599~602
[69] Y. Mizuguchi, K. Deguchi, S. Tsuda, et al., Fabrication of the Iron-Based Superconducting Wire Using Fe(Se,Te), Applied Physics Express, 2009, 2(8): 083004
[70] S. Thanikaikarasan, T. Mahalingam, M. Raja, et al., Characterization of electroplated FeSe thin films, Journal of Materials Science-Materials in Electronics, 2009, 20(8): 727~734
[71] X.J. Wu, Z.Z. Zhang, J.Y. Zhang, et al., Two-carrier transport and ferromagnetism in FeSe thin films, Journal of Applied Physics, 2008, 103(11): 2936977
[72] N. Hamdadou, J.C. Bernede, A. Khelil, Preparation of iron selenide films by selenization technique, Journal of Crystal Growth, 2002, 241(3): 313~319
[73] Y.F. Nie, E. Brahimi, J.I. Budnick, et al., Suppression of superconductivity in FeSe films under tensile strain, Applied Physics Letters, 2009, 94(24): 242505
[74] C. Barone, S. Pagano, I. Pallecchi, et al., Thermal and voltage activated excess 1/f noise in FeTe0.5Se0.5 epitaxial thin films, Physical Review B, 2011, 83(13): 134523
[75] A. Kumar, P. Kumar, U.V. Waghmare, et al., First-principles analysis of electron correlation, spin ordering and phonons in the normal state of FeSe1-x, Journal of Physics-Condensed Matter, 2010, 22(38): 385701
[76] S. Chandra, A.K.M.A. Islam, Elastic properties of mono- and poly-crystalline PbO-type FeSe1-xTex (x=0-1.0): A first-principles study, Physica C-Superconductivity and Its Applications, 2010, 470(22): 2072~2075
[77] H. Usui, K. Kuroki, Effective five band analysis on the pressure effect of FeSe, Physica C-Superconductivity and Its Applications, 2010, (470): 382~384
[78] H.H. Wen, G. Mu, L. Fang, et al, Superconductivity at 25 K in hole-doped (La1-x Srx )OFeAs, Europhys Lett, 2008, (82): 17009
[79] C.D. Cruz, Q. Huang, J.W. Lynn, et al, Magnetic Order versus Superconductivity in the Iron-Based Layered La (O1 - x Fx )FeAs Systems, Nature, 2008, (453): 899~902
[80] F. Hunte, J. Jaroszynski, A. Gurevich, et al., Two-band superconductivity in LaFeAsO0.89F0.11 at very high magnetic fields, Nature, 2008, 453(7197): 903~905
[81] H. Ding, P. Richard, K. Nakayama, et al., Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2, Epl, 2008, 83(4): 47001
[82] L. Zhao, H.Y. Liu, W.T. Zhang, et al., Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy, Chinese Physics Letters, 2008, 25(12): 4402~4405
[83] R.H. Liu, G. Wu, D.F. Fang, et al, Phase Diagram and Quantum Critical Point in Newly Discovered Superconductors:SmO1-xFxFeAs, Physical Review Letters, 2008, (107): 087 001
[84] L. Shan, Y.L. Wang, X.Y. Zhu, et al, Unconventional Pairing Symmetry in Iron-Based Layered Superconductor LaO0.9F0.1-δFeAs Revealed by Point-Contact Spectroscopy Measurements, Europhysics Letters, 2008, (83): 57004
[85] Y.J. Xia, F.Q. Huang, X.M. Xie, et al., Preparation and superconductivity of stoichiometric beta-FeSe, Epl, 2009, 86(3): 37008
[86] J.C. Grivel, A.C. Wulff, Y. Zhao, et al., In situ observation of the formation of FeSe, Superconductor Science & Technology, 2011, 24(1): 015007
[87]马宗青,铜活化二硼化镁低温烧结机制及超导电性[博士学位论文] ,天津;天津大学, 2011
[88] A.E. Nielsen, Electrolyte crystal growth mechanisms, J. Cryst. Growth., 1984, (67): 289~310
[89] L.M. Fabietti, R.K. Trivedi, Nonequilibrium effects during the ledgewise growth of a solid-liquid interface, Metall. Trans. A., 1991, (22): 1249~1258
[90]胡荣祖,启祯,热分析动力学,北京:科学出版社, 2001: 8～50
[91]史庆志,二硼化镁的形成机理及其成相控制[博士学位论文] ,天津;天津大学, 2008
[92]赵倩,镍掺杂对MgB2相的形成及超导性能的影响[博士学位论文] ,天津;天津大学, 2010
[93] C.D. Doyle, Kinetic analysis of thermogravimetric data, Appl. Polymer. Sci., 1961, 5(15): 285
[94] C. Popescu, Integral method to analyze the kinetics of heter-ogeneous reactions under non-isothermal conditions A varian-t on the Ozawa-Flynn-Wall method, 1996: 208~309
[95] D.J. Gawryluk, J. Fink-Finowicki, A. Wisniewski, et al., Growth conditions, structure and superconductivity of pure and metal-doped FeTe1-xSex single crystals, Superconductor Science & Technology, 2011, 24(6): 065011
[96] M. Eisterer, R. Raunicher, H.W. Weber, et al., Anisotropic critical currents in FeSe0.5Te0.5 films and the influence of neutron irradiation, Superconductor Science & Technology, 2011, 24(6): 065016
[97] M. Hanawa, A. Ichinose, S. Komiya, et al., Substrate Dependence of Structural and Transport Properties in FeSe0.5Te0.5 Thin Films, Japanese Journal of Applied Physics, 2011, 50(5): 053101
[98] C.L. Chen, C.L. Dong, J.L. Chen, et al., X-Ray spectra and electronic correlations of FeSe1-xTex, Physical Chemistry Chemical Physics, 2011, 13(34): 15666~15672
[2]章立源,超越自由,神奇的超导体,北京:科学出版社, 2005, 7: 16~27
[3]韩汝珊,吴勇,超导物理基础,北京:北京大学出版社, 1997: 4~12
[4]林良真,张金龙,李传义等,超导电性及其应用,北京:北京工业大学出版社, 1998: 1~18
[5]刘永长,马宗青, MgB2超导体的成相与掺杂机理,北京:科学出版社, 2009: 1~5
[6] J. Bardeen, L.N. Copper, J.R. Schrieffer, Theory of Superconductivity, Phys.Rev., 1957, (108): 1175~1208
[7] J.R. Gavaler, Superconductivity in Nb-Ge Films above 22K, Appl.Phys.Lett., 1957,( 23): 480~483
[8] J.G. Bednorz, K.A. Muller, Possible high Tc superconductivity in the Ba-La-Cu-O system, Z. Physik, 1986, (64): 189~193
[9] C. Kittel, Introduction to Solid State Physics, 6th ed, 1986: 321
[10]杨遇春,稀土元素在高温超导材料中的应用,稀有金属材料与工程, 2000, 29(2): 78~81
[11]赵忠贤,陈立泉,崔长庚等,近期超导电性研发亮点,科学通报, 1987, (32): 107.
[12] M.K. Wu, J.R. Ashburn, C.J. Torng, et al., Superconductivity at 93 K in a new mixed-phase Y-Ba-Cu-O compound system at ambient pressure, Phys.Rev.Lett., 1987, (58): 908~910
[13] Z. Tarnawski, N.T.H. Kim-Ngan, X.Z. Wang, et al., Specific heat of RBa2Cu3O7-x and RBaSrCu3O7-x compounds (R = Sm, Dy, Er), Acta Physica Polonica A, 1998, 93(3): 513~522
[14] L.P. Kozeeva, M.Y. Kameneva, A.N. Lavrov, et al., Growth, morphology, and superconducting properties of RBa2Cu3O7-x (R = Tm, Lu) single crystals, Inorganic Materials, 1998, 34(10): 1057~1064
[15] J.A. McAllister, J.P. Attfield, Cation disorder effects in RBa2Cu3O7-x superconductors, International Journal of Inorganic Materials, 1999, 1(34): 269~271
[16] S.A. Antony, K.S. Nagaraja, S. Sahasranaman, et al., Complete chemical control of stoichiometry of materials related to high Tc ceramics RBa2Cu3O7-x (R = rare earth), Physica C-Superconductivity and Its Applications, 1999, 323(34): 115~121
[17] E. Gmelin, S.M. Sarge, Temperature, heat and heat flow rate calibration of differential scanning calorimeters, Thermochimica Acta, 2000, 347(12): 9~13
[18] V.F. Masterov, F.S. Nasredinov, N.P. Seregin, et al., Charge states of atoms in the lattices of the high-temperature superconductors Tl2Ba2Can-1CunO2n+4 and Bi2Sr2Can-1CunO2n+4, Journal of Experimental and Theoretical Physics, 1998, 87(3): 588~593
[19] L. Jansen, R. Block, Effect of iodine intercalation on superconductivity in the high- Tc series Bi2Sr2CaN-1CuNO2N+4+delta, N=1-3, and in the yttrium doped N=2 compound. A quantitative analysis on the basis of indirect exchange pairing, Physica A, 2000, 277(12): 183~203
[20] H. Maeda, M. Fukitomi,et al., A new high- Tc oxide superconductor without a rare earth element, App.Phys., 1988, 27(2): 209~210
[21] T. Sato, H. Matsui, S. Nishina, et al., Low energy excitation and scaling in Bi2Sr2Can-1CunO2n+4 (n=1-3): Angle-resolved photoemission spectroscopy, Physical Review Letters, 2002, 89(6): 067005
[22] Z.Z. Sheng, A.M. Hermann, Bulk superconductivity at 120 K in the Ti–Ca/Ba–Cu–O system, Nature, 1988, (332): 138~139
[23] D. Sedmidubsky, J. Leitner, K. Knizek, et al., Phase relations in Hg-Ba-Ca-Cu-O system, Physica C-Superconductivity and Its Applications, 2000, (341): 509~510
[24] C.W. Chu, Evidence for novel polaronic Fermi-liquid in doped oxides, Physica C-Superconductivity and Its Applications, 2000, (25): 341~346
[25]张裕恒,超导物理,合肥:中国科学技术大学出版社, 2009, 1~28
[26] W. Meissner, R. Ochsenfeld, Einneuer effect bei eintrit der supraleifahigheit, NatureWissenschaften, 1933, (21): 787
[27] C.A. Reynolds, B. Serin, W.H. Wright, et al., Superconductivity of isotopes of Mercury, Phys. Rev., 1950, (78): 487
[28] E. Maxwell, Isotope effect in superconductivity of Mercury, Phys. Rev., 1950, (78): 477
[29] Y. Kamihara, H. Hiramatsu, M. Hirano, et al., Iron-based layered superconductor: LaOFeP, Journal of the American Chemical Society, 2006, 128(31): 10012~10013
[30] Y. Kamihara, T. Watanabe, M. Hirano, et al., Iron-based layered superconductor La[O1-xFx]FeAs (x=0.05-0.12) with Tc =26 K, Journal of the American Chemical Society, 2008, 130(11): 3296
[31]马廷灿,万勇,姜山,铁基超导材料制备研究进展,科学通报, 2009, 54(5): 557~568
[32] I.R. Shein, A.L. Ivanovskii, Band structure of SrFeAsF and CaFeAsF-the base phases of a new group of oxygen-free FeAs superconductors, Jetp Letters, 2008, 88(10): 683~687
[33] P. Cheng, B. Shen, G. Mu, et al., High- Tc superconductivity induced by doping rare-earth elements into CaFeAsF, Epl, 2009, 85(6): 67003
[34] X.Z. Jin, T. Watanabe, K. Takase, et al., Electrical and magnetic properties of La deficient superconductor La1-xOFeP, Journal of Alloys and Compounds, 2009, 488(1): 14~16
[35] H. Takahashi, K. Igawa, K. Arii, et al., Superconductivity at 43 K in an iron-based layered compound LaO1-xFxFeAs, Nature, 2008, 453(7193): 376~378
[36] Z.A. Ren, G.C. Che, X.L. Dong, et al., Superconductivity and phase diagram in iron-based arsenic-oxides ReFeAsO1-delta (Re = rare-earth metal) without fluorine doping, Epl, 2008, 83(1): 17002
[37] Z. Wei, H.O. Li, W.L. Hong, et al., Superconductivity at 57.3 K in La-doped iron-based layered compound Sm0.95La0.05O0.85F0.15FeAs, Journal of Superconductivity and Novel Magnetism, 2008, 21(4): 213~215
[38] M. Rotter, M. Tegel, D. Johrendt, et al., Spin-density-wave anomaly at 140 K in the ternary iron arsenide BaFe2As2, Physical Review B, 2008, 78(2): 4021
[39] M. Rotter, M. Pangerl, M. Tegel, et al., Superconductivity and crystal structures of (Ba1-xKx)Fe2AS2 (x=0-1), Angewandte Chemie-International Edition, 2008, 47(41): 7949~7952
[40] Z. Li, J.S. Tse, C.Q. Jin, Bonding in the "111" Type Ferropnictide Superconductor LiFeAs, Journal of Superconductivity and Novel Magnetism, 2010, 23(5): 579~581
[41] D.R. Parker, M.J. Pitcher, P.J. Baker, et al., Structure, antiferromagnetism and superconductivity of the layered iron arsenide NaFeAs, Chemical Communications, 2009, (16): 2189~2191
[42] X.C. Wang, Q.Q. Liu, Y.X. Lv, et al., The superconductivity at 18 K in LiFeAs system, Solid State Communications, 2008, 148(12): 538~540
[43] K.W. Yeh, T.W. Huang, Y.L. Huang, et al., Tellurium substitution effect on superconductivity of the alpha-phase iron selenide, Epl, 2008, 84(3): 37002
[44] D.J. Gawryluk, J. Fink-Finowicki, A. Wisniewski, et al., Structure and Superconductivity of FeSe1-x and FeTe1-ySey Crystals: Dependence on the Synthesis Methods, Starting Composition, and Growth Conditions, Acta Physica Polonica A, 2010, 118(2): 331~335
[45] F.C. Hsu, J.Y. Luo, K.W. Yeh, et al., Superconductivity in the PbO-type structure alpha-FeSe, Proceedings of the National Academy of Sciences of the United States of America, 2008, 105(38): 14262~14264
[46] C.L. Song, Y.L. Wang, P. Cheng, et al., Direct Observation of Nodes and Twofold Symmetry in FeSe Superconductor, Science, 2011, 332(6036): 1410~1413
[47] T.M. McQueen, Q. Huang, V. Ksenofontov, et al., Extreme sensitivity of superconductivity to stoichiometry in Fe1+deltaSe, Physical Review B, 2009, 79(1): 014522
[48] A.J. Williams, T.M. McQueen, R.J. Cava, The stoichiometry of FeSe, Solid State Communications, 2009, 149(37-38): 1507~1509
[49] E. Pomjakushina, K. Conder, V. Pomjakushin, et al., Synthesis, crystal structure, and chemical stability of the superconductor FeSe1-x, Physical Review B, 2009, 80(2): 024517
[50] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Substitution Effects on FeSe Superconductor, Journal of the Physical Society of Japan, 2009, 78(7): 07412
[51] R.W. Gomez, V. Marquina, J.L. Perez-Mazariego, et al., Effects of Substituting Se with Te in the FeSe Compound: Structural, Magnetization and Mossbauer Studies, Journal of Superconductivity and Novel Magnetism, 2010, 23(4): 551~557
[52] K.W. Yeh, H.C. Hsu, T.W. Huang, et al., Se and Te Doping Study of the FeSe Superconductors, Journal of the Physical Society of Japan, 2008, (77): 19~22
[53] T.W. Huang, T.K. Chen, K.W. Yeh, et al., Doping-driven structural phase transition and loss of superconductivity in MxFe1-xSedelta (M=Mn, Cu), Physical Review B, 2010, 82(10):104502
[54] A.K. Yadav, A.D. Thakur, C.V. Tomy, Enhanced superconducting properties in FeCrxSe, Solid State Communications, 2011, 151(7): 557~560
[55] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Superconductivity in S-substituted FeTe, Applied Physics Letters, 2009, 94(1): 3058720
[56] M.K. Wu, K.W. Yeh, H.C. Hsu, et al., The development of the superconducting tetragonal PbO-type FeSe and related compounds, Physica Status Solidi B-Basic Solid State Physics, 2010, 247(3): 500~505
[57] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., Superconductivity at 27 K in tetragonal FeSe under high pressure, Applied Physics Letters, 2008, 93(15): 152505
[58] S.S. Naghavi, S. Chadov, C. Felser, The role of correlations in the high-pressure phase of FeSe, Journal of Physics-Condensed Matter, 2011, 23(20): 205601
[59] L.M. Schoop, S.A. Medvedev, V. Ksenofontov, et al., Pressure-restored superconductivity in Cu-substituted FeSe, Physical Review B, 2011, 84(17): 174505
[60] R.S. Kumar, Y. Zhang, S. Sinogeikin, et al., Crystal and Electronic Structure of FeSe at High Pressure and Low Temperature, Journal of Physical Chemistry B, 2010, 114(39): 12597~12606
[61] A. Subedi, L.J. Zhang, D.J. Singh, et al., Density functional study of FeS, FeSe, and FeTe: Electronic structure, magnetism, phonons, and superconductivity, Physical Review B, 2008, 78(13): 134514
[62] Y. Mizuguchi, F. Tomioka, S. Tsuda, et al., FeTe as a candidate material for new iron-based superconductor, Physica C-Superconductivity and Its Applications, 2009, 469(20): 1027~1029
[63] G. Tsoi, A.K. Stemshorn, Y.K. Vohra, et al., High pressure superconductivity in iron-based layered compounds studied using designer diamonds, Journal of Physics-Condensed Matter, 2009, 21(23): 232201
[64] Y.P. Sun, S.B. Zhang, X.D. Zhu, et al., Superconductivity of FeSe0.89 crystal with hexagonal and tetragonal structures, Superconductor Science & Technology, 2009, 22(7): 075016
[65] B.H. Mok, S.M. Rao, M.C. Ling, et al., Growth and Investigation of Crystals of the New Superconductor alpha-FeSe from KCl Solutions, Crystal Growth & Design, 2009, 9(7): 3260~3264
[66] Z.L. Xiao, U. Patel, J. Hua, et al., Growth and superconductivity of FeSex crystals, Applied Physics Letters, 2009, 94(8): 082508
[67] K.W. Yeh, C.T. Ke, T.W. Huang, et al., Superconducting FeSe1-xTex Single Crystals Grown by Optical Zone-Melting Technique, Crystal Growth & Design, 2009, 9(11): 4847~4851
[68] O. Tkachenko, A. Morawski, A. Zaleski, et al., Synthesis, Crystal Growth and Epitaxial Layers Growth of FeSe0,88 Superconductor and Other Poison Materials by Use of High Gas Pressure Trap System, Journal of Superconductivity and Novel Magnetism, 2009, 22(6): 599~602
[69] Y. Mizuguchi, K. Deguchi, S. Tsuda, et al., Fabrication of the Iron-Based Superconducting Wire Using Fe(Se,Te), Applied Physics Express, 2009, 2(8): 083004
[70] S. Thanikaikarasan, T. Mahalingam, M. Raja, et al., Characterization of electroplated FeSe thin films, Journal of Materials Science-Materials in Electronics, 2009, 20(8): 727~734
[71] X.J. Wu, Z.Z. Zhang, J.Y. Zhang, et al., Two-carrier transport and ferromagnetism in FeSe thin films, Journal of Applied Physics, 2008, 103(11): 2936977
[72] N. Hamdadou, J.C. Bernede, A. Khelil, Preparation of iron selenide films by selenization technique, Journal of Crystal Growth, 2002, 241(3): 313~319
[73] Y.F. Nie, E. Brahimi, J.I. Budnick, et al., Suppression of superconductivity in FeSe films under tensile strain, Applied Physics Letters, 2009, 94(24): 242505
[74] C. Barone, S. Pagano, I. Pallecchi, et al., Thermal and voltage activated excess 1/f noise in FeTe0.5Se0.5 epitaxial thin films, Physical Review B, 2011, 83(13): 134523
[75] A. Kumar, P. Kumar, U.V. Waghmare, et al., First-principles analysis of electron correlation, spin ordering and phonons in the normal state of FeSe1-x, Journal of Physics-Condensed Matter, 2010, 22(38): 385701
[76] S. Chandra, A.K.M.A. Islam, Elastic properties of mono- and poly-crystalline PbO-type FeSe1-xTex (x=0-1.0): A first-principles study, Physica C-Superconductivity and Its Applications, 2010, 470(22): 2072~2075
[77] H. Usui, K. Kuroki, Effective five band analysis on the pressure effect of FeSe, Physica C-Superconductivity and Its Applications, 2010, (470): 382~384
[78] H.H. Wen, G. Mu, L. Fang, et al, Superconductivity at 25 K in hole-doped (La1-x Srx )OFeAs, Europhys Lett, 2008, (82): 17009
[79] C.D. Cruz, Q. Huang, J.W. Lynn, et al, Magnetic Order versus Superconductivity in the Iron-Based Layered La (O1 - x Fx )FeAs Systems, Nature, 2008, (453): 899~902
[80] F. Hunte, J. Jaroszynski, A. Gurevich, et al., Two-band superconductivity in LaFeAsO0.89F0.11 at very high magnetic fields, Nature, 2008, 453(7197): 903~905
[81] H. Ding, P. Richard, K. Nakayama, et al., Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2, Epl, 2008, 83(4): 47001
[82] L. Zhao, H.Y. Liu, W.T. Zhang, et al., Multiple Nodeless Superconducting Gaps in (Ba0.6K0.4)Fe2As2 Superconductor from Angle-Resolved Photoemission Spectroscopy, Chinese Physics Letters, 2008, 25(12): 4402~4405
[83] R.H. Liu, G. Wu, D.F. Fang, et al, Phase Diagram and Quantum Critical Point in Newly Discovered Superconductors:SmO1-xFxFeAs, Physical Review Letters, 2008, (107): 087 001
[84] L. Shan, Y.L. Wang, X.Y. Zhu, et al, Unconventional Pairing Symmetry in Iron-Based Layered Superconductor LaO0.9F0.1-δFeAs Revealed by Point-Contact Spectroscopy Measurements, Europhysics Letters, 2008, (83): 57004
[85] Y.J. Xia, F.Q. Huang, X.M. Xie, et al., Preparation and superconductivity of stoichiometric beta-FeSe, Epl, 2009, 86(3): 37008
[86] J.C. Grivel, A.C. Wulff, Y. Zhao, et al., In situ observation of the formation of FeSe, Superconductor Science & Technology, 2011, 24(1): 015007
[87]马宗青,铜活化二硼化镁低温烧结机制及超导电性[博士学位论文] ,天津;天津大学, 2011
[88] A.E. Nielsen, Electrolyte crystal growth mechanisms, J. Cryst. Growth., 1984, (67): 289~310
[89] L.M. Fabietti, R.K. Trivedi, Nonequilibrium effects during the ledgewise growth of a solid-liquid interface, Metall. Trans. A., 1991, (22): 1249~1258
[90]胡荣祖,启祯,热分析动力学,北京:科学出版社, 2001: 8～50
[91]史庆志,二硼化镁的形成机理及其成相控制[博士学位论文] ,天津;天津大学, 2008
[92]赵倩,镍掺杂对MgB2相的形成及超导性能的影响[博士学位论文] ,天津;天津大学, 2010
[93] C.D. Doyle, Kinetic analysis of thermogravimetric data, Appl. Polymer. Sci., 1961, 5(15): 285
[94] C. Popescu, Integral method to analyze the kinetics of heter-ogeneous reactions under non-isothermal conditions A varian-t on the Ozawa-Flynn-Wall method, 1996: 208~309
[95] D.J. Gawryluk, J. Fink-Finowicki, A. Wisniewski, et al., Growth conditions, structure and superconductivity of pure and metal-doped FeTe1-xSex single crystals, Superconductor Science & Technology, 2011, 24(6): 065011
[96] M. Eisterer, R. Raunicher, H.W. Weber, et al., Anisotropic critical currents in FeSe0.5Te0.5 films and the influence of neutron irradiation, Superconductor Science & Technology, 2011, 24(6): 065016
[97] M. Hanawa, A. Ichinose, S. Komiya, et al., Substrate Dependence of Structural and Transport Properties in FeSe0.5Te0.5 Thin Films, Japanese Journal of Applied Physics, 2011, 50(5): 053101
[98] C.L. Chen, C.L. Dong, J.L. Chen, et al., X-Ray spectra and electronic correlations of FeSe1-xTex, Physical Chemistry Chemical Physics, 2011, 13(34): 15666~15672