TSMTG法制备GdBCO块材及对其性能的研究
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摘要
顶部籽晶熔融织构法(TSMTG)是制备钇系高温超导块材的重要技术之一。在钇系超导材料中,GdBCO超导体具有较高的临界温度、较大的无阻载流能力和较强的磁通捕获能力,因而在超导电机、超导磁悬浮列车、磁浮轴承、永磁体、储能飞轮等方面都具有巨大的应用价值。
本文采用固相烧结法制备出比较纯的初始粉体,采用TSMTG工艺制各出掺杂不同BaCuO2 (Gd011)含量的GdBCO单畴超导块材,并对该类超导块材的微观结构和磁悬浮力等性能进行了分析；其次,通过在GdBa2Cu3O7-δ(Gd123)初始粉体中掺杂不同含量的Y2O3粉体,制备出了系列(Gd, Y)BCO超导块材,在对其宏观形貌,微观结构和磁悬浮力性能进行分析的基础上,研究了工艺参数对超导块材形貌和性能的影响。
在制备GdBCO超导体的过程中,需要用到GdBa2Cu3O7-δ(Gd123)、Gd2BaCuO5(Gd211)和BaCuO2 (Gd011)等初始粉体。这些粉体均采用多次研磨多次烧结的工艺,三种粉体的烧结温度分别为940℃,920℃,910℃。
研究了BaCuO2添加对TSMTG法单畴GdBCO块材的生长形貌、微观结构以及磁悬浮力性能的影响。在固定Gd123与Gd211摩尔比为1：0.4时,当Gd011掺杂量在0-0.5mol范围内时,Gd011的掺杂对其表面形貌影响不大,均可制备出单畴GdBCO块材。对整个组分进行的微观结构分析结果表明：随着Gd011掺杂比例的增加,Gd211粒子的尺寸在逐渐地减小。这是由于过量Gd011致使Gd211在液相中溶解的结果。另外,我们研究了Gd211粒子在准单畴GdBCO超导块材中的分布。对掺杂Gd011为0.2mol的准单畴样品分析结果表明,Gd211粒子在整个样品中分布都是不均匀的。对该系列超导块材磁悬浮力测试的结果表明,Gd011的含量对GdBCO超导体的磁悬浮力有明显影响,在固定Gd123与Gd211摩尔比为1：0.4时,掺杂BaCuO2的最佳比例约为0.2mol。
研究了Y2O3添加对TSMTG法(Gd, Y)BCO超导块材的生长形貌、微观结构以及磁悬浮力性能的影响。当在Gd123初始粉体中添加Y2O3质量分数较小时,畴区长满整个样品；当两者质量比例超过100：4时,随着添加的Y2O3质量的增加,样品表面所形成的单畴区域面积逐渐减小；当两者质量比例超过100：15时,样品完全停止生长。对其生长前沿成份分析结果表明,成份偏析是导致晶体生长停止的主要原因。对掺杂Y2O3粉体的样品,随着掺杂量的增加,镶嵌在样品中的RE211粒子密度逐渐增加,同时RE123相含量逐渐减少。磁悬浮力测试结果表明,Y2O3的含量对(Gd, Y)BCO超导块的磁悬浮力有明显影响,其最佳添加质量比为Gd123：Y2O3=100：4。温度参数的选择对(Gd, Y)BCO超导块形貌和性能的影响也很大,最高融化温度过高过低都不好,通过多次调整得到最佳熔化温度为1070℃。生长温区的选择直接关系到样品生长的好坏,通过四组不同的生长温区试验得到相对最佳生长温区。
The top seeded melt texture growth (TSMTG) process is one of the most effective methods for fabricating large YBCO bulk superconductors. The single-domain YBCO samples can be prepared by TSMTG in a large size YBCO. The GdBa2Cu3O7-δbulk superconductors have significant potential for practical applications, such as superconducting motors, maglev, magnetic bearings, permanent magnets, flywheel energy storage systems etc, since they have high critical temperature(Tc), high critical current density(Jc) and high trapped magnetic fields.
In this paper, the precusor powder was prepared by the solid- state reaction method. Single domain GdBCO bulk superconductors with different BaCuO2 additions were prepared by top-seeded melt texture growth technique, meanwhile, their microstructure and levitation force were analyzed systematically. Secondly, TSMTG (Gd,Y)BCO bulk superconductors have been fabricated by mixing Y2O3 and GdBa2Cu3O7-δ(Gd123) in different mass ratio, meanwhile, their microstructure and levitation force were analyzed systematically. In addition, the influence of the processing parameters on the properties and growth morphology of (Gd,Y)BCO bulk superconductors have also been studied.
During the preparation of the GdBCO bulk superconductor, GdBa2Cu3O7-δ(Gd123)、Gd2BaCuO5(Gd211) and BaCuO2(Gd011) powders were synthesized by sintering and grinding process alternatively for several times, their sintering temperature is 940℃、920℃、910℃respectively.
The effect of BaCuO2 addition on the growth morphology, microstructure and levitation force of single domain GdBCO bulk superconductor have been investigated. The results indicate that single domain GdBCO bulk samples can be fabricated with the precursors of Gd123:Gd211:Gd011 =1:0.4:x(x=0, 0.1, 0.2,0.3,0.4,0.5). The microstructure of the samples showes that the average Gd211 particles size was gradually decreased with increasing BaCuO2 addition. The decrease could be explained by a reaction between Gd211 and liquid phase due to excess BaCuO2 content which can consume Gd211. Additionally, the distribution of Gd211 particles in the quasi-single domain GdBCO bulk superconductor were investigated, scan electron microscope (SEM) analysis results show that the Gd211 particles are not uniformly distributed in the Gd123 matrix. The magnetic levitation force measurement results show that the levitation force of the samples is much different with different additions of BaCuO2. It is found that the optimal initial molar ratio is Gd123:Gd211: Gd011=1:0.4:0.2.
The effect of Y2O3 addition on the growth morphology, microstructure and levitation force of single domain GdBCO bulk superconductor by the top-seeded melt texture growth process(TSMTG) has been studied. The results show that when Y2O3 addition is in a little ration, single domain (Gd,Y)BCO bulk can be obtained; when the mass ratio is larger than 100:4, the single domain area decreases monotonically with increasing Y2O3; when the mass ratio is higher than 100:15, there is nearly no distinct superconducting phases in the sample. The chemical component analysis of the crystal growth front indicates that the reason for the stopping growth of (Gd,Y)BCO crystal is because of the distinct deviation of the Gd3+、Y3+、Ba2+ and Cu2+ from the standard chemical ratio for (Gd,Y)BCO crystal growth. In those samples prepared with Y2O3 additions, the density of RE211 particles were monotonically increased with increasing Y2O3, meanwhile, RE123 content were gradually decreased. The magnetic levitation force is much different for the samples with different Y2O3 additions. It is found that the optimal mass ratio is 100:4 for preparation of (Gd,Y)BCO bulk superconductors. Besides, the influence of the heat processing parameters on the properties and growth morphology of (Gd,Y)BCO bulk superconductors have been studied. Too high or too low of the maximum melting tempreture(Tmax) is going to depress the crystal growth, the optimal Tmax is about 1070℃. The growth tempreture window is directly related to sample quality, the optimal growth tempreture window has been determined by some experiments.
本文采用固相烧结法制备出比较纯的初始粉体,采用TSMTG工艺制各出掺杂不同BaCuO2 (Gd011)含量的GdBCO单畴超导块材,并对该类超导块材的微观结构和磁悬浮力等性能进行了分析；其次,通过在GdBa2Cu3O7-δ(Gd123)初始粉体中掺杂不同含量的Y2O3粉体,制备出了系列(Gd, Y)BCO超导块材,在对其宏观形貌,微观结构和磁悬浮力性能进行分析的基础上,研究了工艺参数对超导块材形貌和性能的影响。
在制备GdBCO超导体的过程中,需要用到GdBa2Cu3O7-δ(Gd123)、Gd2BaCuO5(Gd211)和BaCuO2 (Gd011)等初始粉体。这些粉体均采用多次研磨多次烧结的工艺,三种粉体的烧结温度分别为940℃,920℃,910℃。
研究了BaCuO2添加对TSMTG法单畴GdBCO块材的生长形貌、微观结构以及磁悬浮力性能的影响。在固定Gd123与Gd211摩尔比为1：0.4时,当Gd011掺杂量在0-0.5mol范围内时,Gd011的掺杂对其表面形貌影响不大,均可制备出单畴GdBCO块材。对整个组分进行的微观结构分析结果表明：随着Gd011掺杂比例的增加,Gd211粒子的尺寸在逐渐地减小。这是由于过量Gd011致使Gd211在液相中溶解的结果。另外,我们研究了Gd211粒子在准单畴GdBCO超导块材中的分布。对掺杂Gd011为0.2mol的准单畴样品分析结果表明,Gd211粒子在整个样品中分布都是不均匀的。对该系列超导块材磁悬浮力测试的结果表明,Gd011的含量对GdBCO超导体的磁悬浮力有明显影响,在固定Gd123与Gd211摩尔比为1：0.4时,掺杂BaCuO2的最佳比例约为0.2mol。
研究了Y2O3添加对TSMTG法(Gd, Y)BCO超导块材的生长形貌、微观结构以及磁悬浮力性能的影响。当在Gd123初始粉体中添加Y2O3质量分数较小时,畴区长满整个样品；当两者质量比例超过100：4时,随着添加的Y2O3质量的增加,样品表面所形成的单畴区域面积逐渐减小；当两者质量比例超过100：15时,样品完全停止生长。对其生长前沿成份分析结果表明,成份偏析是导致晶体生长停止的主要原因。对掺杂Y2O3粉体的样品,随着掺杂量的增加,镶嵌在样品中的RE211粒子密度逐渐增加,同时RE123相含量逐渐减少。磁悬浮力测试结果表明,Y2O3的含量对(Gd, Y)BCO超导块的磁悬浮力有明显影响,其最佳添加质量比为Gd123：Y2O3=100：4。温度参数的选择对(Gd, Y)BCO超导块形貌和性能的影响也很大,最高融化温度过高过低都不好,通过多次调整得到最佳熔化温度为1070℃。生长温区的选择直接关系到样品生长的好坏,通过四组不同的生长温区试验得到相对最佳生长温区。
The top seeded melt texture growth (TSMTG) process is one of the most effective methods for fabricating large YBCO bulk superconductors. The single-domain YBCO samples can be prepared by TSMTG in a large size YBCO. The GdBa2Cu3O7-δbulk superconductors have significant potential for practical applications, such as superconducting motors, maglev, magnetic bearings, permanent magnets, flywheel energy storage systems etc, since they have high critical temperature(Tc), high critical current density(Jc) and high trapped magnetic fields.
In this paper, the precusor powder was prepared by the solid- state reaction method. Single domain GdBCO bulk superconductors with different BaCuO2 additions were prepared by top-seeded melt texture growth technique, meanwhile, their microstructure and levitation force were analyzed systematically. Secondly, TSMTG (Gd,Y)BCO bulk superconductors have been fabricated by mixing Y2O3 and GdBa2Cu3O7-δ(Gd123) in different mass ratio, meanwhile, their microstructure and levitation force were analyzed systematically. In addition, the influence of the processing parameters on the properties and growth morphology of (Gd,Y)BCO bulk superconductors have also been studied.
During the preparation of the GdBCO bulk superconductor, GdBa2Cu3O7-δ(Gd123)、Gd2BaCuO5(Gd211) and BaCuO2(Gd011) powders were synthesized by sintering and grinding process alternatively for several times, their sintering temperature is 940℃、920℃、910℃respectively.
The effect of BaCuO2 addition on the growth morphology, microstructure and levitation force of single domain GdBCO bulk superconductor have been investigated. The results indicate that single domain GdBCO bulk samples can be fabricated with the precursors of Gd123:Gd211:Gd011 =1:0.4:x(x=0, 0.1, 0.2,0.3,0.4,0.5). The microstructure of the samples showes that the average Gd211 particles size was gradually decreased with increasing BaCuO2 addition. The decrease could be explained by a reaction between Gd211 and liquid phase due to excess BaCuO2 content which can consume Gd211. Additionally, the distribution of Gd211 particles in the quasi-single domain GdBCO bulk superconductor were investigated, scan electron microscope (SEM) analysis results show that the Gd211 particles are not uniformly distributed in the Gd123 matrix. The magnetic levitation force measurement results show that the levitation force of the samples is much different with different additions of BaCuO2. It is found that the optimal initial molar ratio is Gd123:Gd211: Gd011=1:0.4:0.2.
The effect of Y2O3 addition on the growth morphology, microstructure and levitation force of single domain GdBCO bulk superconductor by the top-seeded melt texture growth process(TSMTG) has been studied. The results show that when Y2O3 addition is in a little ration, single domain (Gd,Y)BCO bulk can be obtained; when the mass ratio is larger than 100:4, the single domain area decreases monotonically with increasing Y2O3; when the mass ratio is higher than 100:15, there is nearly no distinct superconducting phases in the sample. The chemical component analysis of the crystal growth front indicates that the reason for the stopping growth of (Gd,Y)BCO crystal is because of the distinct deviation of the Gd3+、Y3+、Ba2+ and Cu2+ from the standard chemical ratio for (Gd,Y)BCO crystal growth. In those samples prepared with Y2O3 additions, the density of RE211 particles were monotonically increased with increasing Y2O3, meanwhile, RE123 content were gradually decreased. The magnetic levitation force is much different for the samples with different Y2O3 additions. It is found that the optimal mass ratio is 100:4 for preparation of (Gd,Y)BCO bulk superconductors. Besides, the influence of the heat processing parameters on the properties and growth morphology of (Gd,Y)BCO bulk superconductors have been studied. Too high or too low of the maximum melting tempreture(Tmax) is going to depress the crystal growth, the optimal Tmax is about 1070℃. The growth tempreture window is directly related to sample quality, the optimal growth tempreture window has been determined by some experiments.
引文
[1]章立源,张金龙,崔广霁等.超导物理[M].北京：电子工业出版社,1987：1-3
[2]C.P.Bean, Rev.Mod. Phys,63,31(1964).
[3]T.Matsushita, M.Kiuchi et al. Supercond.Sci.Techonl,2006,19:200.
[4]赵忠贤,陈立泉,杨乾声等.液氮温区的氧化物超导体[J].科学通报.1987.
[5]C.W.Chu, P.H.Hor, R.I.Meng. Some New High-Tc Superconductors. Phys. Rev.Lett,1987.
[6]章立源.超越自由神奇的超导体[M].北京：科学出版社,2005：6.
[7]韩汝珊,伍勇.超导物理基础[M].北京：北京大学出版社,1997：9-10.
[8]Meissner W and Ochsenfeld R. Naturwissenshaften[J].1933,21:787-788.
[9]I. S. Gergis et al,55 GHz microstrip bandpass filter made from YBa2Cu3O7-δ superconductor thin film [J]. Appl. Phys. Lett,1992,60:2026.
[10]S. Verghese, et al. Fabrication of an infrared bolometer with a high Tc superconducting thermometer [J]. IEEET rans. Magn,1991,27:3077～3080.
[11]W.D.Kingery, H.K.Bowen, D.R.Uhlmann. Introduction to Ceramics(John Wiley & Sons,New York,1976).
[12]刘光华,稀土材料与应用技术[M].北京：化学工业出版社,2005：427-433.
[13]G.Fuchs, G.Krabbes, P.Schatzle, et al. High trapped fields in melt-textured YBCO samples[J]. Physica C,1996,268:115-120.
[14]M.Muiakami, N.Sakai et al. Melt-proceSsed light rare earth element-Ba-Cu-O[J], Supercond. Sci.Technol,1996,9:1015.
[15]Nan Chen, K C Goretta et al. Effect of heating rate on properties of YBa2Cu3O7-x [J].Supercon.Sci.Technol,1988,1:177-179.
[16]Chung Wei Cheng,A C Rose-Innes,N MCn Alford,et al.The effect of porosity on the superconducting properties of YBa2Cu3O7-δ ceramic[J]. Supercond. Sci. Technol,1988,1:113-117.
[17]Jin S, Teifel T H et al. High critical current density in bulk Y-Ba-Cu-O superconductors[J]. Applied Physics Letters,1988,52:2074-2076.
[18]Salama K, Selvamanickam V, Gao L, et al. High current density in bulk YBa2Cu3O7-δ superconductor[J]. Applied Physics Letters.1989,54: 2352-2354.
[19]M Murakami, M Morita et al. A New process with the promise fo high Jc in oxide superconductors [J]. Jpn. J. Phy,1989,28:1189-1194.
[20]Shi D, Sengupta S et al. Extremely fine precipitates and flux pinning in melt-processed YBa2Cu3Ox[J]. Physica C,1993,213(1-2):179-184.
[21]L.Zhou, P.X.zhang et al. Supercond.Sci.Technol.1990,3:490.
[22]肖玲,任洪涛,焦玉磊,郑明辉.REBaCuO单畴超导块的研究与进展[J].低温物理学报,2003,25,增刊,309-314.
[23]S.Kohayashi, S.Yoshizawa. Large domain growth of Ag-doped YBaCuO-system superconductor[J]. Materials Science and Engineering,1998, B53: 70-74.
[24]H.W.Neumuller, W.Nick, B.Wacker. Advances in and prospects for development of high-temperature superconductor rotating machines at Siemens[J]. Supercond.Sci.Technol,2006,19:S114-S117.
[25]Y. Zhao, J. S. Wang, S. Y. Wang. Applications of YBCO melt textured bulks in Maglev technology [J]. Physica C,2004,412-414:771-777.
[26]A. M. Campbell and D.A. Cardwell. Bulk high temperature superconductors for magnet applitations[J]. PⅡ,1997, SOO11-2275:00068-4.
[27]S.Nariki, N.Sakai, M.Murakami. Melt-processed Gd-Ba-Cu-0 superconduct-or with trapped field of 3T at 77K[J]. Superocnd.Sci.Technol,2005,18: 126-130.
[28]S Nariki, H.Hinai. Effect of microstructure on the superconducting properties of GdBaCuO bulk fabricated in air[J]. Physica C,2001,358-360:817-820
[29]Nariki S,Sakai N,Murakami M.Physica C[J],2002,378-381:631-635
[30]S.Haseyamaetal, Advances in Superconductivity XI, Springer,Tokyo,1999, p.701
[31]A.Hua, N.Sakai et al. Air processing of ternary (Sm,Eu,Gd)Ba2Cu3O7-δ super-conductors with enhanced peak effects[J]. Physica C,2004,402:127-135.
[32]Y. Nakamura, A. Shibusawa. Effect of growth anisotropy on the morphology and property of directionally solidified RE123[J]. Physica C,2005,426-431: 1026-1032.
[33]S.Nariki, N.Sakai. Fabrication and superconducting properties of Gd-Ba-Cu-0 single-grain bulk with barium cerate addition[J]. Physica C,2006,445-448: 291-294
[34]Caixuan Xu, Anming Hu. Flux pinning properties and superconductivity of Gd-123 superconductor with addition of nanosized SnO2/ZrO2 particles[J]. Physica C,2006,445-448:357-360.
[35]S.Nariki, N.Sakai, K.Inoue. Effect of Ag addition on cold-seeded melt-growth of Gd-Ba-Cu-0 superconductor using Nd123 seed crystal[J]. Physica C,2003, 392-396:468-472.
[36]S.Nariki, N.Sakai,M.Murakami.Preparation and properties of OCMG-processed Gd-Ba-Cu-0 bulk superconductors with very fine Gd211 particals[J]. Physic C,2001,357-360:811-813.
[37]裴佳良.单畴GdBCO超导体的制备及物性研究[D].西安：陕西师范大学,2008
[38]AHu, N Sakai et al.Single-grain growth, microstructure and superconducting properties of (Sm,Eu)123 superconductors with BaCuO2-x addition[J].16 (2003),33-38
[39]Dai J Q, Zhao Z X, Xiong J W. The influence of BaCuO2-δ in Gd-Ba-Cu-0 single-grain superconductors fabricated in air. Supercond Sci Technol [J],2003, 16:815-819
[40]A. Hu, N. Sakai. Large grain growth and superconducting properties of GdBa2Cu3O7-x fabricated in air with BaCuO2-x addition[J]. Physica C,2003, 386:275-278.
[41]刘兆梅.顶部籽晶熔渗法单畴YBCO超导体的制备及其性能研究[D].西安：陕西师范大学,2008.
[42]武晓亮.GdBa2Cu3O7-δ超导体的研制[D].西安：陕西师范大学,2007.
[43]Caixuan Xu,AnmingHu et al. Effect of BaO2 and fine Gd2BaCuO7-δ addition on the superconducting properties of air-processe GdBa2Cu3O7-δ [J]. Supercond. Sci. Technol,2005,18:229-233
[44]Meignan T, Mcginn P J et al. Supercond. Sci. Technol,1997,10:109
[45]何豫生,蔡丽英,向炯等.关于高Tc的超导体在100K-300K的晶格不稳定性问题[J].高温超导体.1988,4：137-141
[46]Y. Shi, N. Hari Babu et al.Properties of GdBCO bulk superconductors melt-rocessed in air using a Mg-doped Nd-Ba-Cu-0 genericseed crystal[J]. Supercond. Sci. Technol,2007,20:38-43
[47]Y. Shi, N. Hari Babu et al. Growth Rate and Superconducting Properties of Gd-Ba-Cu-O Bulk Superconductors Melt Processed in Air[J]. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY,2007,17: 2984-2987.
[48]席少波.元素掺杂对单畴YBCO超导体性能的影响[D].西安：陕西师范大学,2008.
[49]Kim C J and Hong G-W. Supercond. Sci. Technol.1999,12:27
[50]Y2BaCuO5粒子在准单畴Y-Ba-Cu-O超导块材中的分布及其对超导性能的影响[J].无机材料学报,2008,23：13-18.
[51]Cima M J, Flemings M C et al. Appl.Phys,1992,71:1868-1871.
[52]S.H. Hsu, I.G. Chen et al. Supercond. Sci. Technol,2002,15:653.
[53]D.A. Cardwell, A.D. Bradley et al. Supercond. Sci. Technol,2002,15:639.
[54]Murakami M,Yamaguchi.K et al. Cryogenics,1992,32:930.
[55]S.Jin, T.H.Tiefel et al. Superconducting properties of YBa2Cu3O7-δ with partial rare earth substitution[J]. Physica C,1991,173:75-79.
[56]杜社军等.用PMP法制备的Y-Gd-Ba-Cu-O超导体及其性能[J].低温与超导,1994,24：37-41.
[57]冯勇等.PMP法YGdBaCu-O超导体的磁通钉扎研究[J].物理学报,2000,49：146-151.
[58]陈镇平等.替代YBa2Cu3O7-δ超导体的相结构与局域电子结构的研究[J].物理学报,2005,54：5382-5388.
[59]N.I. Matskevich, T.L. Popova, E.S. Zolotova, M.A. Starikov, Thermochim. Acta,1995,254:41.
[60]S.Nariki, N.Sakai et al. Effect of RE2BaCuO5 refinement on the critical current density and trapped field of melt-textured (Gd, Y)-Ba-Cu-0 bulk superconductors[J]. Physica C,2006,439:62-66.
[61]H.Zheng,M.Jiang et al. Growth and physical properties of melt textured (Gd,Y)Ba2Cu3Ox[J]. Physica C,1998.307:284-290.
[62]M. Murakami. Melt Processed High-Temperature Superconductors, in:M. Murakami(Ed), World Scientific, Chap.2.
[63]C.Varanasi, P.J.McGinn et al. Physica C,1994,221:46-52.
[64]S. Nariki, S-J. Supercond. Sci. Technol,2000,13:778.
[65]杨万民,周廉,冯勇,张平祥,吴民智.过量Y203的添加对熔融织构YBCO大块性能的影响[J].中国科学,2003,33(4)：333-339.
[66]T.Saitoh, K.Segawa et al. Microstructures and superconducting properties of melt-processed of (RE,RE')-Ba-Cu-O[J]. Physica C,1997,288:141-147.
[67]Wanmin Yang, Lian Zhou et al. Analysis of the morphology and chemical composition at the growth front of YBCO bulks[J]. Physica C,2000,337: 288-291.
[68]M.Murakami. Melt Processing of high-temperatur superconductors. Progress In Materials Science,1994,38:311-357.
[69]Yang W M, Chao X X, Bian X B, Liu P, Feng Y, Zhang P X, Zhou L. The effect of magnet size on the levitation force and attractive force of single-domain YBCO bulk superconductors[J]. Supercond.Sci.Technol,2003, 16:789-792.
[70]Lee D F, Selvamanickam V, Salama K. Influences of Y2BaCuO5 partical size and content on the transpot critical current density of YBa2Cu3Ox superconductor[J]. Physica C,1992,202:83-96.
[71]Y.A.Jee, G.W.Hong et al. Supercond.Sci.Technol,1998,11:650.
[72]Y.A.Jee, G.W.Hong et al. Physica C,1999,314:211.
[73]白云强.Sm-Ba-Cu-O超导块材的制备及性能研究[D].成都：西南交通大学.2008.
[2]C.P.Bean, Rev.Mod. Phys,63,31(1964).
[3]T.Matsushita, M.Kiuchi et al. Supercond.Sci.Techonl,2006,19:200.
[4]赵忠贤,陈立泉,杨乾声等.液氮温区的氧化物超导体[J].科学通报.1987.
[5]C.W.Chu, P.H.Hor, R.I.Meng. Some New High-Tc Superconductors. Phys. Rev.Lett,1987.
[6]章立源.超越自由神奇的超导体[M].北京：科学出版社,2005：6.
[7]韩汝珊,伍勇.超导物理基础[M].北京：北京大学出版社,1997：9-10.
[8]Meissner W and Ochsenfeld R. Naturwissenshaften[J].1933,21:787-788.
[9]I. S. Gergis et al,55 GHz microstrip bandpass filter made from YBa2Cu3O7-δ superconductor thin film [J]. Appl. Phys. Lett,1992,60:2026.
[10]S. Verghese, et al. Fabrication of an infrared bolometer with a high Tc superconducting thermometer [J]. IEEET rans. Magn,1991,27:3077～3080.
[11]W.D.Kingery, H.K.Bowen, D.R.Uhlmann. Introduction to Ceramics(John Wiley & Sons,New York,1976).
[12]刘光华,稀土材料与应用技术[M].北京：化学工业出版社,2005：427-433.
[13]G.Fuchs, G.Krabbes, P.Schatzle, et al. High trapped fields in melt-textured YBCO samples[J]. Physica C,1996,268:115-120.
[14]M.Muiakami, N.Sakai et al. Melt-proceSsed light rare earth element-Ba-Cu-O[J], Supercond. Sci.Technol,1996,9:1015.
[15]Nan Chen, K C Goretta et al. Effect of heating rate on properties of YBa2Cu3O7-x [J].Supercon.Sci.Technol,1988,1:177-179.
[16]Chung Wei Cheng,A C Rose-Innes,N MCn Alford,et al.The effect of porosity on the superconducting properties of YBa2Cu3O7-δ ceramic[J]. Supercond. Sci. Technol,1988,1:113-117.
[17]Jin S, Teifel T H et al. High critical current density in bulk Y-Ba-Cu-O superconductors[J]. Applied Physics Letters,1988,52:2074-2076.
[18]Salama K, Selvamanickam V, Gao L, et al. High current density in bulk YBa2Cu3O7-δ superconductor[J]. Applied Physics Letters.1989,54: 2352-2354.
[19]M Murakami, M Morita et al. A New process with the promise fo high Jc in oxide superconductors [J]. Jpn. J. Phy,1989,28:1189-1194.
[20]Shi D, Sengupta S et al. Extremely fine precipitates and flux pinning in melt-processed YBa2Cu3Ox[J]. Physica C,1993,213(1-2):179-184.
[21]L.Zhou, P.X.zhang et al. Supercond.Sci.Technol.1990,3:490.
[22]肖玲,任洪涛,焦玉磊,郑明辉.REBaCuO单畴超导块的研究与进展[J].低温物理学报,2003,25,增刊,309-314.
[23]S.Kohayashi, S.Yoshizawa. Large domain growth of Ag-doped YBaCuO-system superconductor[J]. Materials Science and Engineering,1998, B53: 70-74.
[24]H.W.Neumuller, W.Nick, B.Wacker. Advances in and prospects for development of high-temperature superconductor rotating machines at Siemens[J]. Supercond.Sci.Technol,2006,19:S114-S117.
[25]Y. Zhao, J. S. Wang, S. Y. Wang. Applications of YBCO melt textured bulks in Maglev technology [J]. Physica C,2004,412-414:771-777.
[26]A. M. Campbell and D.A. Cardwell. Bulk high temperature superconductors for magnet applitations[J]. PⅡ,1997, SOO11-2275:00068-4.
[27]S.Nariki, N.Sakai, M.Murakami. Melt-processed Gd-Ba-Cu-0 superconduct-or with trapped field of 3T at 77K[J]. Superocnd.Sci.Technol,2005,18: 126-130.
[28]S Nariki, H.Hinai. Effect of microstructure on the superconducting properties of GdBaCuO bulk fabricated in air[J]. Physica C,2001,358-360:817-820
[29]Nariki S,Sakai N,Murakami M.Physica C[J],2002,378-381:631-635
[30]S.Haseyamaetal, Advances in Superconductivity XI, Springer,Tokyo,1999, p.701
[31]A.Hua, N.Sakai et al. Air processing of ternary (Sm,Eu,Gd)Ba2Cu3O7-δ super-conductors with enhanced peak effects[J]. Physica C,2004,402:127-135.
[32]Y. Nakamura, A. Shibusawa. Effect of growth anisotropy on the morphology and property of directionally solidified RE123[J]. Physica C,2005,426-431: 1026-1032.
[33]S.Nariki, N.Sakai. Fabrication and superconducting properties of Gd-Ba-Cu-0 single-grain bulk with barium cerate addition[J]. Physica C,2006,445-448: 291-294
[34]Caixuan Xu, Anming Hu. Flux pinning properties and superconductivity of Gd-123 superconductor with addition of nanosized SnO2/ZrO2 particles[J]. Physica C,2006,445-448:357-360.
[35]S.Nariki, N.Sakai, K.Inoue. Effect of Ag addition on cold-seeded melt-growth of Gd-Ba-Cu-0 superconductor using Nd123 seed crystal[J]. Physica C,2003, 392-396:468-472.
[36]S.Nariki, N.Sakai,M.Murakami.Preparation and properties of OCMG-processed Gd-Ba-Cu-0 bulk superconductors with very fine Gd211 particals[J]. Physic C,2001,357-360:811-813.
[37]裴佳良.单畴GdBCO超导体的制备及物性研究[D].西安：陕西师范大学,2008
[38]AHu, N Sakai et al.Single-grain growth, microstructure and superconducting properties of (Sm,Eu)123 superconductors with BaCuO2-x addition[J].16 (2003),33-38
[39]Dai J Q, Zhao Z X, Xiong J W. The influence of BaCuO2-δ in Gd-Ba-Cu-0 single-grain superconductors fabricated in air. Supercond Sci Technol [J],2003, 16:815-819
[40]A. Hu, N. Sakai. Large grain growth and superconducting properties of GdBa2Cu3O7-x fabricated in air with BaCuO2-x addition[J]. Physica C,2003, 386:275-278.
[41]刘兆梅.顶部籽晶熔渗法单畴YBCO超导体的制备及其性能研究[D].西安：陕西师范大学,2008.
[42]武晓亮.GdBa2Cu3O7-δ超导体的研制[D].西安：陕西师范大学,2007.
[43]Caixuan Xu,AnmingHu et al. Effect of BaO2 and fine Gd2BaCuO7-δ addition on the superconducting properties of air-processe GdBa2Cu3O7-δ [J]. Supercond. Sci. Technol,2005,18:229-233
[44]Meignan T, Mcginn P J et al. Supercond. Sci. Technol,1997,10:109
[45]何豫生,蔡丽英,向炯等.关于高Tc的超导体在100K-300K的晶格不稳定性问题[J].高温超导体.1988,4：137-141
[46]Y. Shi, N. Hari Babu et al.Properties of GdBCO bulk superconductors melt-rocessed in air using a Mg-doped Nd-Ba-Cu-0 genericseed crystal[J]. Supercond. Sci. Technol,2007,20:38-43
[47]Y. Shi, N. Hari Babu et al. Growth Rate and Superconducting Properties of Gd-Ba-Cu-O Bulk Superconductors Melt Processed in Air[J]. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY,2007,17: 2984-2987.
[48]席少波.元素掺杂对单畴YBCO超导体性能的影响[D].西安：陕西师范大学,2008.
[49]Kim C J and Hong G-W. Supercond. Sci. Technol.1999,12:27
[50]Y2BaCuO5粒子在准单畴Y-Ba-Cu-O超导块材中的分布及其对超导性能的影响[J].无机材料学报,2008,23：13-18.
[51]Cima M J, Flemings M C et al. Appl.Phys,1992,71:1868-1871.
[52]S.H. Hsu, I.G. Chen et al. Supercond. Sci. Technol,2002,15:653.
[53]D.A. Cardwell, A.D. Bradley et al. Supercond. Sci. Technol,2002,15:639.
[54]Murakami M,Yamaguchi.K et al. Cryogenics,1992,32:930.
[55]S.Jin, T.H.Tiefel et al. Superconducting properties of YBa2Cu3O7-δ with partial rare earth substitution[J]. Physica C,1991,173:75-79.
[56]杜社军等.用PMP法制备的Y-Gd-Ba-Cu-O超导体及其性能[J].低温与超导,1994,24：37-41.
[57]冯勇等.PMP法YGdBaCu-O超导体的磁通钉扎研究[J].物理学报,2000,49：146-151.
[58]陈镇平等.替代YBa2Cu3O7-δ超导体的相结构与局域电子结构的研究[J].物理学报,2005,54：5382-5388.
[59]N.I. Matskevich, T.L. Popova, E.S. Zolotova, M.A. Starikov, Thermochim. Acta,1995,254:41.
[60]S.Nariki, N.Sakai et al. Effect of RE2BaCuO5 refinement on the critical current density and trapped field of melt-textured (Gd, Y)-Ba-Cu-0 bulk superconductors[J]. Physica C,2006,439:62-66.
[61]H.Zheng,M.Jiang et al. Growth and physical properties of melt textured (Gd,Y)Ba2Cu3Ox[J]. Physica C,1998.307:284-290.
[62]M. Murakami. Melt Processed High-Temperature Superconductors, in:M. Murakami(Ed), World Scientific, Chap.2.
[63]C.Varanasi, P.J.McGinn et al. Physica C,1994,221:46-52.
[64]S. Nariki, S-J. Supercond. Sci. Technol,2000,13:778.
[65]杨万民,周廉,冯勇,张平祥,吴民智.过量Y203的添加对熔融织构YBCO大块性能的影响[J].中国科学,2003,33(4)：333-339.
[66]T.Saitoh, K.Segawa et al. Microstructures and superconducting properties of melt-processed of (RE,RE')-Ba-Cu-O[J]. Physica C,1997,288:141-147.
[67]Wanmin Yang, Lian Zhou et al. Analysis of the morphology and chemical composition at the growth front of YBCO bulks[J]. Physica C,2000,337: 288-291.
[68]M.Murakami. Melt Processing of high-temperatur superconductors. Progress In Materials Science,1994,38:311-357.
[69]Yang W M, Chao X X, Bian X B, Liu P, Feng Y, Zhang P X, Zhou L. The effect of magnet size on the levitation force and attractive force of single-domain YBCO bulk superconductors[J]. Supercond.Sci.Technol,2003, 16:789-792.
[70]Lee D F, Selvamanickam V, Salama K. Influences of Y2BaCuO5 partical size and content on the transpot critical current density of YBa2Cu3Ox superconductor[J]. Physica C,1992,202:83-96.
[71]Y.A.Jee, G.W.Hong et al. Supercond.Sci.Technol,1998,11:650.
[72]Y.A.Jee, G.W.Hong et al. Physica C,1999,314:211.
[73]白云强.Sm-Ba-Cu-O超导块材的制备及性能研究[D].成都：西南交通大学.2008.