强磁场用第二代高温超导带材研究进展与挑战
|
摘要
强磁体应用是高温超导材料研究的最大驱动力之一.最近基于REBa2Cu3O7-δ(RE123)涂层导体的超导磁体的中心磁场达到了26.4 T,为目前全高温超导磁体的最好水平,超过NbTi-Nb3Sn基超导磁体极限;同时,在低温超导背景场中内插17 T的第二代高温超导(2G-HTS)带材磁体实现了32 T的全超导磁体,打破了该类磁体磁场强度的世界纪录.这些强磁场技术的突破正是基于高温超导材料的进步,充分显示了高温超导材料在强磁场应用中的诱人前景.然而高温超导磁体技术能否得到进一步发展与广泛应用,还取决于高温超导材料的基础性能、成材效率和性价比的改善和提升.本文将介绍第二代高温超导带材及其磁体应用技术的国内外发展现状,主要包括第二代高温超导带材的技术路线、我国低成本化学法产业化发展情况、人工磁通钉扎技术和磁场下传输性能的提高、超导厚度诱导的临界电流密度下降以及焊接、机械性能等强电应用相关的关键科学和技术问题等.
High-field magnet application is one of most driving forces for the development of high temperature superconducting(HTS) materials. Recently, the magnet consisting of ReBa2 Cu3 O7-δ based coated conductors(RE123, also called as secondary-generation high-temperature superconducting tapes, 2 G-HTS) has exhibited the magnetic field as high as 26.4 T, over than the limit of conventional NbTi-Nb3 Sn magnets. As well, an overall superconductor magnet consisting of a 2 G-HTS magnet inserted into the background with low temperature superconducting magnetic field of 17 T gave rise to the magnetic field up to 32 T, reaching a new world record with regard of all superconductor magnets. In reality, these breakouts take place thanks to the latest advances in practical HTS materials, showing the promising future for power applications. The great advantages and promising prospects of RE123 coated conductors over than other practical superconducting materials have spurred the related researches and rapid development of this field worldwide recently. The further development, however, will depend on the fundamental properties, producing yield, and optimum performance/price etc. In the present paper we give a brief introduction to RE123 coated conductor and its typical structure, as well as main technical routes for the scale-up preparation. We introduce the status and development for RE123 coated conductors around the world, including the existing research institutions and technologies they employed. In past decade, people have tested a variety of thin film techniques to realize the biaxial textured RE123 coated conductors epitaxially grown on flexible metallic tapes. For the most institutions working on the preparation of RE123 coated conductor, both IBAD and RABiTS have been used as popular technical routes due to their availability of long textured substrates, the feasibility of controlled buffer growth and the potential for cost-effective processing. At the same time, various thin film coating techniques including sputtering, pulse laser deposition(PLD), metallorganic chemical vapor or solution depositions(MOCVD, MOD) are employed to prepare the coated conductors for both buffer layers and superconducting layers. Particularly, some emerged MOD technologies for preparing superconducting layer with organic addition into the precursor solution or reduced fluorine content precursor solution have been addressed, due to their great potential for a cost-effective and rapid technical route to prepare RE123 coated conductor. It is also demonstrated that the considerable efforts for artificial flux pinning in RE123 coated conductor by introducing nanoparticles and substrate surface decoration have effectively improved the Jc value of RE123 under applied magnet field. The thickness effect of 2 G-HTS is also an important issue, because in most case the critical current density would decrease while the thickness of superconducting layer increases. Such an effect may be suppressed with controlled techniques and microstructures or compositions. The coated conductors may maintain good biaxial texture as the thickness of superconducting layer increase from 1 to 5 μm, leading to huge increase in current-carrying capability of resultant 2 G-HTS tape. It is believed that the mechanical properties of 2 G-HTS tape are better than 1 G-HTS tape, which is very important during the magnet coil winding. Excessive stress relief or Lorentz force would make coils split or deformed. To improve the anisotropy and mechanical properties, people have designed various types of practical conductors with RE123 tape stacks or metal tubes covered. Moreover, the welding technique of 2 G-HTS tape is investigated due to importance on improving the usage rate of short tapes. In summary, the present review introduces the state of the art of 2 G-HTS tape and relevant key science and technical issues, including the technical routes, artificial flux pinning, field dependence and thickness induced degradation of critical current density, joint technologies, as well as power applications, especially in the field of HTS magnet.
High-field magnet application is one of most driving forces for the development of high temperature superconducting(HTS) materials. Recently, the magnet consisting of ReBa2 Cu3 O7-δ based coated conductors(RE123, also called as secondary-generation high-temperature superconducting tapes, 2 G-HTS) has exhibited the magnetic field as high as 26.4 T, over than the limit of conventional NbTi-Nb3 Sn magnets. As well, an overall superconductor magnet consisting of a 2 G-HTS magnet inserted into the background with low temperature superconducting magnetic field of 17 T gave rise to the magnetic field up to 32 T, reaching a new world record with regard of all superconductor magnets. In reality, these breakouts take place thanks to the latest advances in practical HTS materials, showing the promising future for power applications. The great advantages and promising prospects of RE123 coated conductors over than other practical superconducting materials have spurred the related researches and rapid development of this field worldwide recently. The further development, however, will depend on the fundamental properties, producing yield, and optimum performance/price etc. In the present paper we give a brief introduction to RE123 coated conductor and its typical structure, as well as main technical routes for the scale-up preparation. We introduce the status and development for RE123 coated conductors around the world, including the existing research institutions and technologies they employed. In past decade, people have tested a variety of thin film techniques to realize the biaxial textured RE123 coated conductors epitaxially grown on flexible metallic tapes. For the most institutions working on the preparation of RE123 coated conductor, both IBAD and RABiTS have been used as popular technical routes due to their availability of long textured substrates, the feasibility of controlled buffer growth and the potential for cost-effective processing. At the same time, various thin film coating techniques including sputtering, pulse laser deposition(PLD), metallorganic chemical vapor or solution depositions(MOCVD, MOD) are employed to prepare the coated conductors for both buffer layers and superconducting layers. Particularly, some emerged MOD technologies for preparing superconducting layer with organic addition into the precursor solution or reduced fluorine content precursor solution have been addressed, due to their great potential for a cost-effective and rapid technical route to prepare RE123 coated conductor. It is also demonstrated that the considerable efforts for artificial flux pinning in RE123 coated conductor by introducing nanoparticles and substrate surface decoration have effectively improved the Jc value of RE123 under applied magnet field. The thickness effect of 2 G-HTS is also an important issue, because in most case the critical current density would decrease while the thickness of superconducting layer increases. Such an effect may be suppressed with controlled techniques and microstructures or compositions. The coated conductors may maintain good biaxial texture as the thickness of superconducting layer increase from 1 to 5 μm, leading to huge increase in current-carrying capability of resultant 2 G-HTS tape. It is believed that the mechanical properties of 2 G-HTS tape are better than 1 G-HTS tape, which is very important during the magnet coil winding. Excessive stress relief or Lorentz force would make coils split or deformed. To improve the anisotropy and mechanical properties, people have designed various types of practical conductors with RE123 tape stacks or metal tubes covered. Moreover, the welding technique of 2 G-HTS tape is investigated due to importance on improving the usage rate of short tapes. In summary, the present review introduces the state of the art of 2 G-HTS tape and relevant key science and technical issues, including the technical routes, artificial flux pinning, field dependence and thickness induced degradation of critical current density, joint technologies, as well as power applications, especially in the field of HTS magnet.
引文
1 Bondarenko S I,Koverya V P,Krevsun A V,et al.High-temperature superconductors of the family(RE)Ba2Cu3O7-δand their application.Low Temp Phys,2017,43:1125-1151
2 Senatore C,Alessandrini M,Lucarelli A,et al.Progresses and challenges in the development of high-field solenoidal magnets based on RE123 coated conductors.Supercond Sci Technol,2014,27:103001
3 Cai C B,Liu Z Y,Lu Y M,et al.Evolvement and prospect of practical superconducting materials(in Chinese).Mater Chin,2011,30:1-9[蔡传兵,刘志勇,鲁玉明,等.实用超导材料的发展演变及其前景展望.中国材料进展,2011,30:1-9]
4 Cai C B,Pan C Y,Liu Z Y,et al.High temperature superconducting coated conductors(in Chinese).Prog Phys,2007,27:467-490[蔡传兵,潘成远,刘志勇,等.高温超导涂层导体-RE123双轴织构技术及其发展状态.物理学进展,2007,27:467-490]
5 Huang H,Yao C,Dong C,et al.High transport current superconductivity in powder-in-tube Ba0.6K0.4Fe2As2 tapes at 27 T.Supercond Sci Technol,2018,31:015017
6 Christoph M B.Characterization of High Temperature Superconductor Cables for Magnet Toroidal Field Coils of the DEMO Fusion Power Plant.Karlsruhe:KIT Scientific Publishing,2016.79-147
7 Bussmann-Holder A,Keller H,Bianconi A.High-Tc Copper Oxide Superconductors and Related Novel Materials.Berlin:Springer Series in Materials Science,2017
8 Crisan A.Vortices and Nanostructured Superconductors.Berlin:Springer International Publishing,2017
9 Foltyn S R,Civale L,Macmanusdriscoll J L,et al.Materials science challenges for high-temperature superconducting wire.Nat Mater,2007,6:631-642
10 Yoon S,Kim J,Cheon K,et al.26-T 35-mm all-REBCO multi-width no-insulation superconducting magnet.Supercond Sci Technol,2016,04LT04
11 Liu J H,Cheng J S,Wang Q L,et al.Research progress and application of high-field superconducting magnets(in Chinese).Adv Technol Electral Eng Energ,2017,36:1-13[刘建华,程军胜,王秋良,等.高场超导磁体研究进展及其应用.电工电能新技术,2017,36:1-13]
12 Obradors X,Puig T.Coated conductors for power applications:Materials challenges.Supercond Sci Technol,2014,27:044003
13 Larbalestier D,Curevich A,Feldmann D M,et al.High-Tc superconducting materials for electric power applications.Nature,2001,414:368
14 Tsuchiya K,Kikuchi A,Terashima A,et al.Critical current measurement of commercial REBCO conductors at 4.2 K.Cryogenics,2017,85:1-7
15 Service R F.Superconductivity:New wave of electrical wires inches closer to market.Science,2005,308:348
16 Tsuchiya K,Kikuchi A,Terashima A,et al.Critical current characterization of commercial REBCO coated conductors at 4.2 and 77 K.IEEE Trans Appl Supercon,2017,27:6600205
17 Xu A,Delgado L,Gharahcheshmeh M H,et al.Strong correlation between Jc(T,H||c)and Jc(77 K,3 T||c)in Zr-added(Gd,Y)BaCuOcoated conductors at temperatures from 77 K down to 20 K and fields up to 9 T.Supercond Sci Technol,2015,28:082001
18 Selvamanickam V,Gharahcheshmeh M H,Xu A,et al.High critical currents in heavily doped(Gd,Y)Ba2Cu3Ox superconductor tapes.Appl Phys Lett,2015,106:543-870
19 Gupta A,Jagannathan R,Cooper E I,et al.Superconducting oxide films with high transition temperature prepared from metal trifluoroacetate precursors.Appl Phys Lett,1988,52:2077-2079
20 Araki T,Hirabayashi I.Review of a chemical approach to YBa2Cu3O7-x-coated superconductors-Metalorganic deposition using trifluoroacetates.Supercond Sci Technol,2003,16:R71
21 Obradors X,Puig T,Pomar A,et al.Progress towards all-chemical superconducting YBa2Cu3O7-coated conductors.Supercond Sci Technol,2006,19:S13-S26
22 Li M,Yang W,Shu G,et al.Controlled-growth of YBa2Cu3O7-δfilm using modified low-fluorine chemical solution deposition.IEEETrans Appl Supercon,2015,25:6601804
23 Gu Z,Cui C,Yu J,et al.Direct observation of wrinkling and healing evolution for YBa2Cu3O7-δprecursor films prepared by the metalorganic solution method.IEEE Trans Appl Supercon,2016,26:7201807
24 Gu Z H,Yang W T,Bai C Y,et al.Transient liquid assisted nucleation mechanism of YBa2Cu3O7-δin coated conductor films derived by BaF2 process.Chin Phys B,2015,24:413-418
25 Li M J,Liu Z Y,Bai C Y,et al.Artificial control for nucleation and growth rate of YBa2Cu3O7-δcoated conductors prepared by low fluorine chemical solution deposition.Physica C,2017,537:29-33
26 Blatter G,Feigel’Man M V,Geshkenbein V B,et al.Vortices in high-temperature superconductors.Rev Mod Phys,1994,66:1125-1388
27 Tachiki M,Takahashi S.Anisotropy of critical current in layered oxide superconductors.Solid State Commun,1989,72:1083-1086
28 Cai C,Holzapfel B,H?nisch J,et al.Direct evidence for tailorable flux-pinning force and its anisotropy in REBa2Cu3O7-δmultilayers.Phys Rev B,2004,70:212501
29 Hanisch J,Cai C,Stehr V,et al.Formation and pinning properties of growth-controlled nanoscale precipitates in Ba2Cu3O7-δtransition metal quasi-multilayers.Supercond Sci Technol,2006,19:534
30 Cai C B,Holzapfel B,H?nisch J,et al.Magnetotransport and flux pinning characteristics in RBa2Cu3O7-δ(R=Gd,Eu,Nd)and(Gd1/3Eu1/3Nd1/3)Ba2Cu3O7-δhigh-Tc superconducting thin films on SrTiO3(100).Phys Rev B,2004,69:104531
31 MacManus-Driscoll J L,Foltyn S R,Jia Q X.Strongly enhanced current densities in superconducting coated conductors of Ba2Cu3O7-x+BaZrO3.Nat Mater,2004,3:439-443
32 Kwok W K,Welp U,Glatz A,et al.Vortices in high-performance high-temperature superconductors.Rep Prog Phys,2016,79:116501
33 Xu A,Delgado L,Khatri N,et al.Strongly enhanced vortex pinning from 4 to 77 K in magnetic fields up to 31 T in 15 mol%Zr-added(Gd,Y)-Ba-Cu-O superconducting tapes.APL Mater,2014,2:368
34 Palau A,Valles F,Rouco V,et al.Disentangling vortex pinning landscape in chemical solution deposited superconducting YBa2Cu3O7-x films and nanocomposites.Supercond Sci Technol,2018,31:034004
35 Nakaoka K,Yoshida R,Kimura K,et al.Another approach for controlling size and distribution of nanoparticles in coated conductors fabricated by the TFA-MOD method.Supercond Sci Technol,2017,30:055008
36 Eley S,Leroux M,Rupich M W,et al.Decoupling and tuning competing effects of different types of defects on flux creep in irradiated YBa2Cu3O7-δcoated conductors.Supercond Sci Technol,2017,30:015010
37 Rupich M W,Sathyamurthy S,Fleshler S,et al.Engineered pinning landscapes for enhanced 2G coil wire.IEEE Trans Appl Supercon,2016,26:6601904
38 Kim K,Bhattarai K R,Jang J Y,et al.Design and performance estimation of a 35 T 40 mm no-insulation all-REBCO user magnet.Supercond Sci Technol,2017,30:065008
39 Uglietti D,Bykovsky N,Wesche R,et al.Development of HTS conductors for fusion magnets.IEEE Trans Appl Supercon,2015,25:1-6
40 Fu Y,Wang Y,Kan C,et al.Simulations of bending and twisting mechanical characteristics of a cable strand made of REBCO conductors at cryogenic temperatures.IEEE Trans Appl Supercon,2017,27:1-5
41 Zeng L,Lu Y M,Liu Z Y,et al.Surface texture and interior residual stress variation induced by thickness of YBa2Cu3O7-δthin films.JAppl Phys,2012,112:189
42 Jia Q X,Foltyn S R,Arendt P N,et al.High-temperature superconducting thick films with enhanced supercurrent carrying capability.Appl Phys Lett,2002,80:1601
43 Sun M J,Yang W T,Liu Z Y,et al.Ag doping effects on Y0.5Gd0.5Ba2Cu3O7-δmultilayers derived by low-fluorine metalorganic solution deposition.Mater Res Express,2015,2:096001
44 Lin J,Yang W,Gu Z,et al.Improved epitaxial texture of thick YBa2Cu3O7-δ/GdBa2Cu3O7-δfilms with periodic stress releasing.Supercond Sci Technol,2015,28:045001
45 Lin J,Liu X,Cui C,et al.A review of thickness-induced evolutions of microstructure and superconducting performance of REBa2Cu3O7-δcoated conductor.Adv Manuf,2017,5:165-176
46 Selvamanickam V,Gharahcheshmeh M H,Xu A,et al.Critical current density above 15 MA cm-2 at 30 K,3 T in 2.2μm thick heavilydoped(Gd,Y)Ba2Cu3Ox superconductor tapes.Supercond Sci Technol,2015,2828:072002
47 Malozemoff A P.Progress in American superconductor’s HTS wire and optimization for fault current limiting systems.Physica C,2016,530:65-66
48 Dürrschnabel M,Aabdin Z,Bauer M,et al.DyBa2Cu3O7-x superconducting coated conductors with critical currents exceeding 1000 Acm-1.Supercond Sci Technol,2012,25:105007
49 Zhang Y,Liu W,Zhu X,et al.Unprecedented high irreversibility line in nontoxic cuprate superconductor(Cu,C)Ba2Ca3Cu4O11+δ.2018,arXiv:1805.05830
2 Senatore C,Alessandrini M,Lucarelli A,et al.Progresses and challenges in the development of high-field solenoidal magnets based on RE123 coated conductors.Supercond Sci Technol,2014,27:103001
3 Cai C B,Liu Z Y,Lu Y M,et al.Evolvement and prospect of practical superconducting materials(in Chinese).Mater Chin,2011,30:1-9[蔡传兵,刘志勇,鲁玉明,等.实用超导材料的发展演变及其前景展望.中国材料进展,2011,30:1-9]
4 Cai C B,Pan C Y,Liu Z Y,et al.High temperature superconducting coated conductors(in Chinese).Prog Phys,2007,27:467-490[蔡传兵,潘成远,刘志勇,等.高温超导涂层导体-RE123双轴织构技术及其发展状态.物理学进展,2007,27:467-490]
5 Huang H,Yao C,Dong C,et al.High transport current superconductivity in powder-in-tube Ba0.6K0.4Fe2As2 tapes at 27 T.Supercond Sci Technol,2018,31:015017
6 Christoph M B.Characterization of High Temperature Superconductor Cables for Magnet Toroidal Field Coils of the DEMO Fusion Power Plant.Karlsruhe:KIT Scientific Publishing,2016.79-147
7 Bussmann-Holder A,Keller H,Bianconi A.High-Tc Copper Oxide Superconductors and Related Novel Materials.Berlin:Springer Series in Materials Science,2017
8 Crisan A.Vortices and Nanostructured Superconductors.Berlin:Springer International Publishing,2017
9 Foltyn S R,Civale L,Macmanusdriscoll J L,et al.Materials science challenges for high-temperature superconducting wire.Nat Mater,2007,6:631-642
10 Yoon S,Kim J,Cheon K,et al.26-T 35-mm all-REBCO multi-width no-insulation superconducting magnet.Supercond Sci Technol,2016,04LT04
11 Liu J H,Cheng J S,Wang Q L,et al.Research progress and application of high-field superconducting magnets(in Chinese).Adv Technol Electral Eng Energ,2017,36:1-13[刘建华,程军胜,王秋良,等.高场超导磁体研究进展及其应用.电工电能新技术,2017,36:1-13]
12 Obradors X,Puig T.Coated conductors for power applications:Materials challenges.Supercond Sci Technol,2014,27:044003
13 Larbalestier D,Curevich A,Feldmann D M,et al.High-Tc superconducting materials for electric power applications.Nature,2001,414:368
14 Tsuchiya K,Kikuchi A,Terashima A,et al.Critical current measurement of commercial REBCO conductors at 4.2 K.Cryogenics,2017,85:1-7
15 Service R F.Superconductivity:New wave of electrical wires inches closer to market.Science,2005,308:348
16 Tsuchiya K,Kikuchi A,Terashima A,et al.Critical current characterization of commercial REBCO coated conductors at 4.2 and 77 K.IEEE Trans Appl Supercon,2017,27:6600205
17 Xu A,Delgado L,Gharahcheshmeh M H,et al.Strong correlation between Jc(T,H||c)and Jc(77 K,3 T||c)in Zr-added(Gd,Y)BaCuOcoated conductors at temperatures from 77 K down to 20 K and fields up to 9 T.Supercond Sci Technol,2015,28:082001
18 Selvamanickam V,Gharahcheshmeh M H,Xu A,et al.High critical currents in heavily doped(Gd,Y)Ba2Cu3Ox superconductor tapes.Appl Phys Lett,2015,106:543-870
19 Gupta A,Jagannathan R,Cooper E I,et al.Superconducting oxide films with high transition temperature prepared from metal trifluoroacetate precursors.Appl Phys Lett,1988,52:2077-2079
20 Araki T,Hirabayashi I.Review of a chemical approach to YBa2Cu3O7-x-coated superconductors-Metalorganic deposition using trifluoroacetates.Supercond Sci Technol,2003,16:R71
21 Obradors X,Puig T,Pomar A,et al.Progress towards all-chemical superconducting YBa2Cu3O7-coated conductors.Supercond Sci Technol,2006,19:S13-S26
22 Li M,Yang W,Shu G,et al.Controlled-growth of YBa2Cu3O7-δfilm using modified low-fluorine chemical solution deposition.IEEETrans Appl Supercon,2015,25:6601804
23 Gu Z,Cui C,Yu J,et al.Direct observation of wrinkling and healing evolution for YBa2Cu3O7-δprecursor films prepared by the metalorganic solution method.IEEE Trans Appl Supercon,2016,26:7201807
24 Gu Z H,Yang W T,Bai C Y,et al.Transient liquid assisted nucleation mechanism of YBa2Cu3O7-δin coated conductor films derived by BaF2 process.Chin Phys B,2015,24:413-418
25 Li M J,Liu Z Y,Bai C Y,et al.Artificial control for nucleation and growth rate of YBa2Cu3O7-δcoated conductors prepared by low fluorine chemical solution deposition.Physica C,2017,537:29-33
26 Blatter G,Feigel’Man M V,Geshkenbein V B,et al.Vortices in high-temperature superconductors.Rev Mod Phys,1994,66:1125-1388
27 Tachiki M,Takahashi S.Anisotropy of critical current in layered oxide superconductors.Solid State Commun,1989,72:1083-1086
28 Cai C,Holzapfel B,H?nisch J,et al.Direct evidence for tailorable flux-pinning force and its anisotropy in REBa2Cu3O7-δmultilayers.Phys Rev B,2004,70:212501
29 Hanisch J,Cai C,Stehr V,et al.Formation and pinning properties of growth-controlled nanoscale precipitates in Ba2Cu3O7-δtransition metal quasi-multilayers.Supercond Sci Technol,2006,19:534
30 Cai C B,Holzapfel B,H?nisch J,et al.Magnetotransport and flux pinning characteristics in RBa2Cu3O7-δ(R=Gd,Eu,Nd)and(Gd1/3Eu1/3Nd1/3)Ba2Cu3O7-δhigh-Tc superconducting thin films on SrTiO3(100).Phys Rev B,2004,69:104531
31 MacManus-Driscoll J L,Foltyn S R,Jia Q X.Strongly enhanced current densities in superconducting coated conductors of Ba2Cu3O7-x+BaZrO3.Nat Mater,2004,3:439-443
32 Kwok W K,Welp U,Glatz A,et al.Vortices in high-performance high-temperature superconductors.Rep Prog Phys,2016,79:116501
33 Xu A,Delgado L,Khatri N,et al.Strongly enhanced vortex pinning from 4 to 77 K in magnetic fields up to 31 T in 15 mol%Zr-added(Gd,Y)-Ba-Cu-O superconducting tapes.APL Mater,2014,2:368
34 Palau A,Valles F,Rouco V,et al.Disentangling vortex pinning landscape in chemical solution deposited superconducting YBa2Cu3O7-x films and nanocomposites.Supercond Sci Technol,2018,31:034004
35 Nakaoka K,Yoshida R,Kimura K,et al.Another approach for controlling size and distribution of nanoparticles in coated conductors fabricated by the TFA-MOD method.Supercond Sci Technol,2017,30:055008
36 Eley S,Leroux M,Rupich M W,et al.Decoupling and tuning competing effects of different types of defects on flux creep in irradiated YBa2Cu3O7-δcoated conductors.Supercond Sci Technol,2017,30:015010
37 Rupich M W,Sathyamurthy S,Fleshler S,et al.Engineered pinning landscapes for enhanced 2G coil wire.IEEE Trans Appl Supercon,2016,26:6601904
38 Kim K,Bhattarai K R,Jang J Y,et al.Design and performance estimation of a 35 T 40 mm no-insulation all-REBCO user magnet.Supercond Sci Technol,2017,30:065008
39 Uglietti D,Bykovsky N,Wesche R,et al.Development of HTS conductors for fusion magnets.IEEE Trans Appl Supercon,2015,25:1-6
40 Fu Y,Wang Y,Kan C,et al.Simulations of bending and twisting mechanical characteristics of a cable strand made of REBCO conductors at cryogenic temperatures.IEEE Trans Appl Supercon,2017,27:1-5
41 Zeng L,Lu Y M,Liu Z Y,et al.Surface texture and interior residual stress variation induced by thickness of YBa2Cu3O7-δthin films.JAppl Phys,2012,112:189
42 Jia Q X,Foltyn S R,Arendt P N,et al.High-temperature superconducting thick films with enhanced supercurrent carrying capability.Appl Phys Lett,2002,80:1601
43 Sun M J,Yang W T,Liu Z Y,et al.Ag doping effects on Y0.5Gd0.5Ba2Cu3O7-δmultilayers derived by low-fluorine metalorganic solution deposition.Mater Res Express,2015,2:096001
44 Lin J,Yang W,Gu Z,et al.Improved epitaxial texture of thick YBa2Cu3O7-δ/GdBa2Cu3O7-δfilms with periodic stress releasing.Supercond Sci Technol,2015,28:045001
45 Lin J,Liu X,Cui C,et al.A review of thickness-induced evolutions of microstructure and superconducting performance of REBa2Cu3O7-δcoated conductor.Adv Manuf,2017,5:165-176
46 Selvamanickam V,Gharahcheshmeh M H,Xu A,et al.Critical current density above 15 MA cm-2 at 30 K,3 T in 2.2μm thick heavilydoped(Gd,Y)Ba2Cu3Ox superconductor tapes.Supercond Sci Technol,2015,2828:072002
47 Malozemoff A P.Progress in American superconductor’s HTS wire and optimization for fault current limiting systems.Physica C,2016,530:65-66
48 Dürrschnabel M,Aabdin Z,Bauer M,et al.DyBa2Cu3O7-x superconducting coated conductors with critical currents exceeding 1000 Acm-1.Supercond Sci Technol,2012,25:105007
49 Zhang Y,Liu W,Zhu X,et al.Unprecedented high irreversibility line in nontoxic cuprate superconductor(Cu,C)Ba2Ca3Cu4O11+δ.2018,arXiv:1805.05830