Vortex Pinning Centers in High-Temperature Superconducting Films: History
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Contributor:
Jian Zhang
,
Haiyan Wu
,
Guangzhen Zhao
,
Lu Han
,
Jun Zhang

To better pin the vortex at external magnetic fields, the HTS films must contain APCs with desired morphology, dimension, orientation, and concentration. Nanoscale APCs with lateral dimension approaching 2ξ (coherence length) on the order of a few nanometers in HTSs must be generated to suppress the dissipation of vortex motion. This has prompted extensive efforts and exciting results have been obtained in generating nanoscale APCs in HTS films. The research progress of different types and dimensions APCs in detail is introduced and the impact on superconducting performance is summarized.

  • high-temperature superconducting films
  • vortex pinning
  • artificial pinning center
  • nanoparticle
  • nanocolumn

1. Introduction

Superconductors are a class of materials with unique physical properties and high application value. Within critical parameters, superconductors have two major properties, namely: the zero-resistance effect and the Meissner effect. Tc (critical transition temperature), Bc (critical magnetic field), and Jc (critical current density) are the main critical parameters of superconductors. Currently, superconductors are classified into Type-I and Type-II superconductors. For the Type-I superconductor, there is only one critical magnetic field Bc. However, for the Type-II superconductor, there are two critical magnetic fields, the lower Bc1 and upper Bc2. When Bc1 > B, the superconductor remains in the Meissner state, completely expelling the magnetic flux from its interior. For Bc2 > B > Bc1, the magnetic flux starts penetrating the sample in the form of discrete bundles termed “flux lines” and the sample goes into the mixed state (or vortex state). When B > Bc2, the superconductor comes into the normal state.
Usually, Type-II superconductors that exhibit superconducting states at ~30 K and above are called high-temperature superconductors (HTSs). They are first discovered in 1986 by J. G. Bednorz and K. A. Müller in the Ba-La-Cu-O system [1]. YBa2Cu3O7-δ (YBCO) is the first HTS to be found with Tc above the liquid nitrogen temperature (LN2, 77 K) [2], and its discovery triggers a research boom in the field of superconductivity. Early research on HTS focused on exploring superconductors with higher Tc, and scientists subsequently discovered several systems such as Bi2Sr2Ca2Cu3O10+δ (BSCCO) [3], Tl2Ba2Ca2Cu3O10+δ (TlBCCO) [4], HgBa2Ca2Cu3O8+δ (HgBCCO) [5], all with Tc~77 K and above. Since HTSs allow the use of LN2 as a cooling source, which is readily available and relatively inexpensive, they have a significant cost advantage over low-temperature superconductors (LTS) for future large-scale practical applications [6][7]. Mahesh Paidpilli et al. summarized in detail the various applications of HTSs in the high magnetic field in the United States at present in their review [8]. D. Uglietti summarized relevant research and developments in commercial HTS materials applied in large solenoids, accelerator dipoles, and high-field tokamaks [9]. In addition, other prominent applications of HTS including single-photon detectors based on superconducting nanowires (SNSPDs) [10], superconducting quantum interference devices (SQUIDs) [11][12][13] et al. have also been reported.
For HTS films, commonly used substrates include MgO, SrTiO3, LaAlO3, LaSrAlO4, YSZ (Yttria-Stabilized Zirconia), sapphire (with Ag, CeO2, and MgO buffer layers), and so on [14][15]. Due to the structural complexity, the phase composition of HTS films can vary depending on the deposition methods and parameters (e.g., substrate types, temperature, vacuum quality, accelerating voltage, etc.), resulting in different calcined phases. In addition, individual elements may be present in the form of metal oxides or compounds, and the generation of these additional phases increases the difficulty of preparing HTS films [16][17][18][19][20][21][22].

2. Artificial Pinning Centers (APCs)

To better pin the vortex at external magnetic fields, the HTS films must contain APCs with desired morphology, dimension, orientation, and concentration. Nanoscale APCs with lateral dimension approaching 2ξ (coherence length) on the order of a few nanometers in HTSs must be generated to suppress the dissipation of vortex motion. This has prompted extensive efforts in the past few decades or so and exciting results have been obtained in generating nanoscale APCs in HTS films. In this section, researchers introduced the research progress of different types and dimensions APCs in detail, and summarized the impact on superconducting performance.

2.1. Zero-Dimensional APCs (0D APCs)

The effect of ionic radii on the Tc of REBCO has been documented in previous work [23]. It is well known that varied rare-earths have different ionic radii. The phenomenon that Tc varies linearly with ionic radius of RE ions has been detected and was attributed to strain-induced charge redistribution between the CuO2 planes and the charge reservoir (CuO-chains). Several rare-earth elements, including Sm, Eu, and Nd, have been doped in place of Y with various molar cationic ratios to enhance the vortex-pinning capabilities of YBCO films [24]. The Y atom in Y-Ba-Cu-O has been totally replaced in certain studies [24][25][26][27] by another rare-earth atom or a mixture of two or more rare-earth atoms, which has improved vortex pinning. Several combinations, including (Gd0.8Er0.2) [26] and (Nd1/3Gd1/3Eu1/3) [27], were published to determine whether the strain caused by lattice mismatch increased when mixtures of rare-earth elements were used instead of a single rare-earth element. Except for the situation when defects were random and unrelated, the enhancement was not notable in any circumstances. There have been attempts to substitute Tb, Ce, Pr, Nd, La, Co, Dy, and Eu at the Y site of YBCO and the RE site of REBCO films [28][29][30][31][32]. The increased density of these substituent nanoprecipitates in doped REBCO films compared to pristine REBCO film led to elevated Jc and Fp values across a wide range of applied magnetic fields, which in turn led to stress field due to lattice mismatch between the phases in the resulting REBCO films.

2.2. One-Dimensional APCs (1D APCs)

The idea of strain engineering has been applied to generate and control the morphology and dimension of APCs embedded in HTS films. According to the elastic strain energy model, the appropriate level of interfacial strain can act as a driving force for the self-assembly of 1D vortex pinning, controlling the morphology [33][34], dimensionality [35][36], orientation [37], and concentration [38]. Numerous studies have shown that 1D columnar APCs grown along the c-axis of REBa2Cu3O7-δ films exhibit strong vortex pinning ability, resulting in high Jc when the applied magnetic field is along the c-axis direction [33][38][39][40].
MacManus-Driscoll et al. [41] first reported the introduction of BaZrO3 secondary phase into YBCO films using the PLD (Pulsed Laser Deposition) technique to enhance the performance. It was found that BaZrO3 nanoparticles and nanocolumns produced significant c-axis orientation-related enhancement of Jc despite its random distribution in the YBCO matrix. Following the work of MacManus-Driscoll et al., 1D BaZrO3 APCs have been intensively investigated. In the subsequent report by Yamada et al. [42], the addition of YSZ (yttrium oxide stabilized zirconium oxide) to YBCO targets resulted in the formation of columnar BaZrO3 nanostructures in YBCO films and would leave a YBCO film matrix containing Ba defects. Self-assembly of vertical arrays of BaZrO3 phases is observed in this composite film. The vertical alignment of these self-assembled BaZrO3 columnar phases was hypothesized to be due to the preferential nucleation of impurity islands in the strain field above the impurity particles [43]. Physical property measurements showed that these self-assembled vertical BaZrO3 phase arrays resulted in strong pinning of vortices, especially when the applied magnetic field was along the c-axis direction. Goyal et al. [44] also reported enhanced pinning of BaZrO3/YBCO nanocomposite films along the c-axis direction. The BaZrO3/YBCO interface is strongly strained due to the high lattice mismatch of 7.7% between BaZrO3 and YBCO, which leads to the formation of a high defect density semi-coherent BaZrO3/YBCO heterointerface [45][46]. This defect is considered the source of the high pinning efficiency achieved at the 1D BaZrO3 magnetic flux pinning centers. 
The search for new vortex pinning materials with smaller lattice mismatches with HTSs is the most effective and likely solution to improve superconductivity. In addition to BaZrO3, 1D-nanostructured materials such as BaSnO3 [47][48][49][50][51][52][53][54][55], BaTiO3 [56], BaHfO3 [47][57][58][59], YBa2(Nb/Ta)O6 [60][61][62][63] have also been successfully introduced into YBCO films using the PLD technique. These 1D APCs provide different degrees of vortex immobilization [47][52][57][58][59][61][62][64]. In all cases, the enhancement of Jc is more pronounced when the applied magnetic field is higher. Mele P et al. [55] reported a record Fp, max value of 28.3 GN/m3 for BaSnO3/YBCO nanocomposite films, reflecting the excellent Jc performance at that time. In addition, the double-perovskite material, YBa2NbO6 (YBNO), was also investigated as 1D APCs and introduced into the superconducting matrix [65]. In another study, Jha A. K. et al. [66] applied surface-modified target method to introduce YBa2NbO6 columns into YBCO films by controlling the rotational speed of the target to control the concentration of YBa2NbO6. YBa2NbO6 nanocolumns were observed to effectively enhance the Jc performance of YBCO films. Furthermore, RE3TaO7 and REBa2TaO6 were also proved to significantly enhance the Jc performance of REBCO films [67][68], and the results indicated that lattice mismatch is a suitable condition to produce high pinning ability in the range of 5~12% [68].
Recently, BaHfO3(BHO) has sparked much interest among researchers as a very promising secondary phase APC, whose nano-inclusions in the form of columnar or spherical structures within the REBCO matrix significantly improve the Jc values of REBCO films deposited on single crystals and metal strips [69][70][71][72][73][74][75][76]. Tobita et al. [69] firstly reported that the BHO-doped GdBa2Cu3Oy(GdBCO) film was deposited by PLD on the IBAD-MgO substrate. The most interesting feature of BHO nanocolumns addition was reported as Jc is undepressed by increasing thickness of the film. By using the LTG (Low-Temperature Growth) technique in PLD, BaHfO3/SmBCO films exhibit very high Fp, max (~28 GN/m3) at 77 K when H is parallel to the c-axis [73]. Even on metal tapes, the BaHfO3/GdBCO nanocomposite films exhibit a large Fp, max (~23.5 GN/m3) and a high irreversibility field (µ0Hirr = 15.8 T) when H is parallel to the c-axis at 77 K [74]. In addition, BaHfO3 nanoparticles were also introduced into YBCO [75] and GdBCO [76] films using the CSD method, which improved the Jc of the nanocomposite films.

2.3. Two-Dimensional APCs (2D APCs)

The deposition of multilayer or quasi-multilayer film structures has also been used in HTS films to improve vortex pinning capabilities. For example, YBCO multilayer films have been prepared using the PLD technique (intermediate layers include: Ag [77], Pd [78], Y2O3 [79][80][81], BaZrO3 [82][83], SrRuO3 [84], SrTiO3 [85], LaCaMnO3 [86], YSZ [87], Y-211 [88], PrBa2Cu3Ox [89] and transition metals Ir [90], Ti, Zr, Hf [91]). The formation of BaMO3 (M = Ti, Zr, Hf, Ir) phases can be observed after the addition of transition metal elements to YBCO films. Not only the Jc enhancement based on YBCO multilayers was observed from the physical property test results, but also the irreversibility lines moved to higher H-T regions [82].

2.4. Three-Dimensional APCs (3D APCs)

To obtain better performance, the ideal materials need to be carefully selected when introducing the secondary phase to the HTS matrix. In terms of pinning efficiency, the spherical secondary phase needs to maintain the proper size and shape, and is required to be uniformly distributed among the superconducting matrix, which is necessary. Therefore, it is not an easy task to find a secondary phase material that will persist in ideal presence and distribution during superconductor synthesis as APCs. At present, many compounds have been applied to investigate the possibility of becoming effective APCs.

2.5. Hybrid 1D + 3D APCs

The 1D columnar APCs perform very well in enhancing Jc, but one of the shortcomings is that the performance of Jc degrades more with the change of direction of applied external magnetic fields. In addition, at higher temperatures, due to thermal excitation, the vortex tends to form a double kink structure, and even if they contain crystal defects in the c-axis direction, the unpinned vortices can still move due to the Lorentz force, resulting in degraded performance. To solve this problem, combinations of APCs with different dimensions have been developed. It has been shown that the simultaneous formation of 1D and 3D APCs can effectively compensate for the lack of performance of 1D columnar APCs only, adapting to applied magnetic fields with different applied directions [92].
Mele et al. [93] reported the combined application of two different types of pinning centers to successfully introduce both BaZrO3 columns and Y2O3 nanoparticles into YBCO films using the PLD technique. Although Jc increased only slightly in the intermediate angular region, the significant decrease of Jc with angle in c-axis direction was significantly improved compared to YBCO films with only BaZrO3 nanocolumns added. Similar results were obtained in a related study by Ding F. Z et al. [94]. Subsequently, combinations of columns with nanoparticles of different materials were also reported to enhance the Jc performance of YBCO films, sufficiently reducing the anisotropy of Jc [49][61][95][96]. For example, BaSnO3 columns and Y2O3 nanoparticles were tried in combination, which significantly enhanced Jc and reduced the anisotropy of Jc [48][96]. TEM studies of YBCO + 3%BaSnO3 and YBCO + 3%BaSnO3 + Y2O3 nanocomposite films showed that only columnar nanostructures were formed in YBCO + BaSnO3 films, while YBCO + BaSnO3 + Y2O3 thin films formed both columnar and spherical nanostructures.

This entry is adapted from the peer-reviewed paper 10.3390/nano12224000

References

  1. Bednorz, J.G.; Müller, K.A. Possible high Tc superconductivity in the Ba-La-Cu-O system. Z. Für Phys. B Condens. Matter 1986, 64, 189–193.
  2. Wu, M.K.; Ashburn, J.R.; Torng, C.J.; Hor, P.H.; Meng, R.L.; Gao, L.; Huang, Z.J.; Wang, Y.Q.; Chu, C.W. 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.
  3. Maeda, H.; Tanaka, Y.; Fukutomi, M.; Asano, T. A New High-Tc Oxide Superconductor without a Rare Earth Element. Jpn J. Appl. Phys. 1988, 27, L209–L210.
  4. Parkin, S.S.P.; Lee, V.Y.; Engler, E.M.; Nazzal, A.I.; Huang, T.C.; Gorman, G.; Savoy, R.; Beyers, R. Bulk superconductivity at 125 K in Tl2Ca2Ba2Cu3Ox. Phys. Rev. Lett. 1988, 60, 2539–2542.
  5. Schilling, A.; Cantoni, M.; Guo, J.D.; Ott, H.R. Superconductivity above 130 K in the Hg-Ba-Ca-Cu-O system. Nature 1993, 363, 56–58.
  6. Yildiz, Y.; Nalbant, M. A review of cryogenic cooling in machining processes. Int. J. Mach. Tools Manuf. 2008, 48, 947–964.
  7. Natsume, K.; Mito, T.; Yanagi, N.; Tamura, H.; Tamada, T.; Shikimachi, K.; Hirano, N.; Nagaya, S. Heat transfer performance of cryogenic oscillating heat pipes for effective cooling of superconducting magnets. Cryogenics 2011, 51, 309–314.
  8. Paidpilli, M.; Selvamanickam, V. Development of RE-Ba-Cu-O superconductors in the U.S. for ultra-high field magnets. Supercond. Sci. Technol. 2022, 35, 043001.
  9. Uglietti, D. A review of commercial high temperature superconducting materials for large magnets: From wires and tapes to cables and conductors. Supercond. Sci. Technol. 2019, 32, 053001.
  10. Arpaia, R.; Golubev, D.; Baghdadi, R.; Ciancio, R.; Dražić, G.; Orgiani, P.; Montemurro, D.; Bauch, T.; Lombardi, F. Transport properties of ultrathin YBa2Cu3O7−δ nanowires: A route to single-photon detection. Phys. Rev. B 2017, 96, 064525.
  11. Trabaldo, E.; Pfeiffer, C.; Andersson, E.; Chukharkin, M.; Arpaia, R.; Montemurro, D.; Kalaboukhov, A.; Winkler, D.; Lombardi, F.; Bauch, T. SQUID Magnetometer Based on Grooved Dayem Nanobridges and a Flux Transformer. IEEE Trans. Appl. Supercond. 2020, 30, 1600904.
  12. Arpaia, R.; Andersson, E.; Kalaboukhov, A.; Schröder, E.; Trabaldo, E.; Ciancio, R.; Dražić, G.; Orgiani, P.; Bauch, T.; Lombardi, F. Untwinned YBa2Cu3O7−δ thin films on MgO substrates: A platform to study strain effects on the local orders in cuprates. Phys. Rev. Mater. 2019, 3, 114804.
  13. Zhang, J.; Wu, H.; Zhao, G.; Han, L.; Zhang, J. A Review on Strain Study of Cuprate Superconductors. Nanomaterials 2022, 12, 3340.
  14. Bondarenko, S.I.; Koverya, V.P.; Krevsun, A.V.; Link, S.I. High-temperature superconductors of the family (RE)Ba2Cu3O7-δ and their application. Low Temp. Phys. 2017, 43, 1125–1151.
  15. Zhang, J.; Wang, W.; Wang, N.; Wang, M.; Qi, Y. Atomic-resolution study on the interface structure and strain state reversion of the Bi2Sr2CuO6+δ/MgO heterostructure. J. Colloid Interf. Sci. 2021, 592, 291–295.
  16. Chikumoto, N.; Lee, S.; Nakao, K.; Tanabe, K. Development of inside-plume PLD process for the fabrication of large Ic(B) REBCO tapes. Phys. C-Supercond. Its Appl. 2009, 469, 1303–1306.
  17. Zhao, Y.; Zhu, J.M.; Jiang, G.Y.; Chen, C.S.; Wu, W.; Zhang, Z.W.; Chen, S.K.; Hong, Y.M.; Hong, Z.Y.; Jin, Z.J.; et al. Progress in fabrication of second generation high temperature superconducting tape at Shanghai Superconductor Technology. Supercond. Sci. Technol. 2019, 32, 044004.
  18. Prusseit, W.; Nemetschek, R.; Hoffmann, C.; Sigl, G.; Lumkemann, A.; Kinder, H. ISD process development for coated conductors. Phys. C-Supercond. Its Appl. 2005, 426, 866–871.
  19. Feys, J.; Vermeir, P.; Lommens, P.; Hopkins, S.C.; Granados, X.; Glowacki, B.A.; Baecker, M.; Reich, E.; Ricard, S.; Holzapfel, B.; et al. Ink-jet printing of YBa2Cu3O7 superconducting coatings and patterns from aqueous solutions. J. Mater. Chem. 2012, 22, 3717–3726.
  20. Li, Y.J.; Zdun, K.; Hope, L.; Xie, J.; Corcoran, S.; Qiao, Y.; Reeves, J.; Lenseth, K.; Selvamanickam, V. Texture development and superconducting properties of YBCO thick films deposited on buffered metal substrates at various deposition rates. IEEE Trans. Appl. Supercond. 2003, 13, 2758–2761.
  21. Schindl, M.; Genoud, J.Y.; Suo, H.; Dhalle, M.; Walker, E.; Flukiger, R. Epitaxial growth of biaxially aligned Y-Ba-Cu-O superconductors by spray pyrolysis on textured Ag ribbons and single crystal substrates. IEEE Trans. Appl. Supercond. 2001, 11, 3313–3316.
  22. Kim, H.S.; Oh, S.S.; Ha, H.S.; Youm, D.; Moon, S.H.; Kim, J.H.; Dou, S.X.; Heo, Y.U.; Wee, S.H.; Goyal, A. Ultra-High Performance, High-Temperature Superconducting Wires via Cost-effective, Scalable, Co-evaporation Process. Sci. Rep. 2014, 4, 4744.
  23. Lin, J.G.; Huang, C.Y.; Xue, Y.Y.; Chu, C.W.; Cao, X.W.; Ho, J.C. Origin of the R-ion effect on Tc in YBa2Cu3O7. Phys. Rev. B 1995, 51, 12900–12903.
  24. Jia, Q.X.; Maiorov, B.; Wang, H.; Lin, Y.; Foltyn, S.R.; Civale, L.; MacManus-Driscoll, J.L. Comparative study of REBa2Cu3O7 films for coated conductors. IEEE Trans. Appl. Supercond. 2005, 15, 2723–2726.
  25. Wee, S.H.; Goyal, A.; Martin, P.M.; Heatherly, L. High in-field critical current densities in epitaxial NdBa2Cu3O7-d films on RABiTS by pulsed laser deposition. Supercond. Sci. Technol. 2006, 19, 865–868.
  26. Konishi, M.; Takahashi, K.; Ibi, A.; Muroga, T.; Miyata, S.; Kobayashi, H.; Yamada, Y.; Shiohara, Y. Jc-B characteristics of RE-Ba-Cu-O (RE = Sm, Er and ) films on PLD-CeO2/IBAD-GZO/metal substrates. Phys. C-Supercond. Its Appl. 2006, 445, 633–636.
  27. Cai, C.; Holzapfel, B.; Hanisch, J.; Fernandez, L.; Schultz, L. Magnetotransport and flux pinning characteristics in RBa2Cu3O7-d (R=Gd,Eu,Nd) and (Gd1/3Eu1/3Nd1/3)Ba2Cu3O7-d high-Tc superconducting thin films on SrTiO3(100). Phys. Rev. B 2004, 69, 104531.
  28. Haugan, T.J.; Campbell, T.A.; Pierce, N.A.; Locke, M.F.; Maartense, I.; Barnes, P.N. Microstructural and superconducting properties of (Y1-xEux)Ba2Cu3O7-δ thin films: x = 0 − 1. Supercond. Sci. Technol. 2008, 21, 025014.
  29. Devi, A.R.; Bai, V.S.; Patanjali, P.V.; Pinto, R.; Kumar, N.H.; Malik, S.K. Enhanced critical current density due to flux pinning from lattice defects in pulsed laser ablated Y1-xDyxBa2Cu3O7-δ thin films. Supercond. Sci. Technol. 2000, 13, 935–939.
  30. Barnes, P.N.; Kell, J.W.; Harrison, B.C.; Haugan, T.J.; Varanasi, C.V.; Rane, M.; Ramos, F. Minute doping with deleterious rare earths in YBa2Cu3O7-δ films for flux pinning enhancements. Appl. Phys. Lett. 2006, 89, 012503.
  31. Horii, S.; Ichinose, A.; Ichino, Y.; Ozaki, T.; Yoshida, Y.; Matsumoto, K.; Mukaida, M.; Shimoyama, J.; Kishio, K. Critical current properties and microstructures in impurity-doped ErBa2Cu3Oy films. Phys. C-Supercond. Its Appl. 2007, 463, 922–926.
  32. Zhou, H.; Maiorov, B.; Wang, H.; MacManus-Driscoll, J.L.; Holesinger, T.G.; Civale, L.; Jia, Q.X.; Foltyn, S.R. Improved microstructure and enhanced low-field Jc in (Y0.67Eu0.33)Ba2Cu3O7-d films. Supercond. Sci. Technol. 2008, 21, 025001.
  33. Shi, J.J.; Wu, J.Z. Micromechanical model for self-organized secondary phase oxide nanorod arrays in epitaxial YBa2Cu3O7-δ films. Philos. Mag. A 2012, 92, 2911–2922.
  34. Miu, L.; Ivan, I.; Miu, D.; Mele, P.; Matsumoto, K.; Mikheenko, P.; Dang, V.S.; Crisan, A. High vortex depinning temperatures in YBCO films with BZO nanorods. J. Supercond. Nov. Magn. 2012, 26, 1167–1173.
  35. Shi, J.J.; Wu, J.Z. Influence of the lattice strain decay on the diameter of self assembled secondary phase nanorod array in epitaxial films. J. Appl. Phys. 2015, 118, 164301.
  36. Wu, J.Z.; Shi, J.J.; Baca, F.J.; Emergo, R.; Wilt, J.; Haugan, T.J. Controlling BaZrO3 nanostructure orientation in YBa2Cu3O7-δ films for a three-dimensional pinning landscape. Supercond. Sci. Technol. 2015, 28, 125009.
  37. Shi, J.J.; Wu, J.Z. Structural transition of secondary phase oxide nanorods in epitaxial YBa2Cu3O7-δ films on vicinal substrates. Philos. Mag. A 2012, 92, 4205–4214.
  38. Wu, J.; Shi, J. Interactive modeling-synthesis-characterization approach towards controllable in situ self-assembly of artificial pinning centers in RE-123 films. Supercond. Sci. Technol. 2017, 30, 103002.
  39. Matsumoto, K.; Mele, P. Artificial pinning center technology to enhance vortex pinning in YBCO coated conductors. Supercond. Sci. Technol. 2010, 23, 014001.
  40. Matsushita, T. Flux pinning in superconducting 123 materials. Supercond. Sci. Technol. 2000, 13, 730–737.
  41. MacManus-Driscoll, J.L.; Foltyn, S.R.; Jia, Q.X.; Wang, H.; Serquis, A.; Civale, L.; Maiorov, B.; Hawley, M.E.; Maley, M.P.; Peterson, D.E. Strongly enhanced current densities in superconducting coated conductors of YBa2Cu3O7–x+BaZrO3. Nat. Mater. 2004, 3, 439–443.
  42. Yamada, Y.; Takahashi, K.; Kobayashi, H.; Konishi, M.; Watanabe, T.; Ibi, A.; Muroga, T.; Miyata, S.; Kato, T.; Hirayama, T.; et al. Epitaxial nanostructure and defects effective for pinning in Y(RE)Ba2Cu3O7-x coated conductors. Appl. Phys. Lett. 2005, 87, 132502.
  43. Shchukin, V.A.; Bimberg, D. Spontaneous ordering of nanostructures on crystal surfaces. Rev. Mod. Phys. 1999, 71, 1125–1171.
  44. Goyal, A.; Kang, S.; Leonard, K.J.; Martin, P.M.; Gapud, A.A.; Varela, M.; Paranthaman, M.; Ijaduola, A.O.; Specht, E.D.; Thompson, J.R.; et al. Irradiation-free, columnar defects comprised of self-assembled nanodots and nanorods resulting in strongly enhanced flux-pinning in YBa2Cu3O7−δ films. Supercond. Sci. Technol. 2005, 18, 1533–1538.
  45. Cantoni, C.; Gao, Y.; Wee, S.H.; Specht, E.D.; Gazquez, J.; Meng, J.; Pennycook, S.J.; Goyal, A. Strain-driven oxygen deficiency in self-assembled, nanostructured, composite oxide films. Acs. Nano 2011, 5, 4783–4789.
  46. Horide, T.; Kametani, F.; Yoshioka, S.; Kitamura, T.; Matsumoto, K. Structural evolution induced by interfacial lattice mismatch in self-organized YBa2Cu3O7−δ nanocomposite film. Acs. Nano 2017, 11, 1780–1788.
  47. Horide, T.; Nagao, S.; Lzutsu, R.; Ishimaru, M.; Kita, R.; Matsumoto, K. Geometric and compositional factors on critical current density in YBa2Cu3O7-d films containing nanorods. Supercond. Sci. Technol. 2018, 31, 065012.
  48. Horide, T.; Kawamura, T.; Matsumoto, K.; Ichinose, A.; Yoshizumi, M.; Izumi, T.; Shiohara, Y.J. Improvement by double artificial pinning centers of BaSnO3 nanorods and Y2O3 nanoparticles in YBa2Cu3O7 coated conductors. Supercond. Sci. Technol. 2013, 26, 075019.
  49. Jha, A.K.; Matsumoto, K.; Horide, T.; Saini, S.; Mele, P.; Ichinose, A.; Yoshida, Y.; Awaji, S. Tailoring the vortex pinning strength of YBCO thin films by systematic incorporation of hybrid artificial pinning centers. Supercond. Sci. Technol. 2015, 28, 114004.
  50. Matsumoto, K.; Horide, T.; Jha, A.K.; Mele, P.; Yoshida, Y.; Awaji, S. Irreversibility fields and critical current densities in strongly pinned YBa2Cu3O7-x films with artificial pinning centers. IEEE Trans. Appl. Supercond. 2015, 25, 8001106.
  51. Mele, P.; Matsumoto, K.; Horide, T.; Ichinose, A.; Mukaida, M.; Yoshida, Y.; Horii, S.; Kita, R. Ultra-high flux pinning properties of BaMO3-doped YBa2Cu3O7-x thin films (M = Zr, Sn). Supercond. Sci. Technol. 2008, 21, 032002.
  52. Mele, P.; Matsumoto, K.; Ichinose, A.; Mukaida, M.; Yoshida, Y.; Horii, S.; Kita, R. Systematic study of BaSnO3 doped YBa2Cu3O7-x films. Phys. C-Supercond. Its Appl. 2009, 469, 1380–1383.
  53. Varanasi, C.V.; Burke, J.; Wang, H.; Lee, J.H.; Barnes, P.N. Thick YBa2Cu3O7-x+BaSnO3 films with enhanced critical current density at high magnetic fields. Appl. Phys. Lett. 2008, 93, 092501.
  54. Varanasi, C.; Burke, J.; Brunke, L.; Wang, H.; Sumption, M.; Barnes, P. Enhancement and angular dependence of transport critical current density in pulsed laser deposited YBa2Cu3O7−x+BaSnO3 films in applied magnetic fields. J. Appl. Phys. 2007, 102, 063909.
  55. Mele, P.; Matsumoto, K.; Ichinose, A.; Mukaida, M.; Yoshida, Y.; Horii, S.; Kita, R. Systematic study of the BaSnO3 insertion effect on the properties of YBa2Cu3O7-x films prepared by pulsed laser ablation. Supercond. Sci. Technol. 2008, 21, 125017.
  56. Jha, A.K.; Khare, N.; Pinto, R. Enhanced flux pinning in pulsed laser deposited YBa2Cu3O7-d:BaTiO3 nanocomposite thin films. Solid State Commun. 2011, 151, 1447–1451.
  57. Gautam, B.; Sebastian, M.A.; Chen, S.; Misra, S.; Huang, J.; Javier Baca, F.; Emergo, R.; Haugan, T.; Xing, Z.; Wang, H.; et al. Probing the effect of interface on vortex pinning efficiency of one-dimensional BaZrO3 and BaHfO3 artificial pinning centers in YBa2Cu3O7-x thin films. Appl. Phys. Lett. 2018, 113, 212602.
  58. Miura, S.; Tsuchiya, Y.; Yoshida, Y.; Ichino, Y.; Awaji, S.; Ichinose, A.; Matsumoto, K.; Ibi, A.; Izumi, T.; Iwakuma, M. Improved Flux Pinning for High-Field Applications in BaHfO3-Doped SmBa2Cu3Oy-Coated Conductors With High Density of Random Pinning Centers Induced by BaHfO3 Nanorods. IEEE Trans. Appl. Supercond. 2018, 28, 1–6.
  59. Miura, S.; Yoshida, Y.; Ichino, Y.; Tsuruta, A.; Matsumoto, K.; Ichinose, A.; Awaji, S. Vortex pinning at low temperature under high magnetic field in SmBa2Cu3Oy superconducting films with high number density and small size of BaHfO3 nano-rods. Supercond. Sci. Technol. 2015, 28, 114006.
  60. Sieger, M.; Pahlke, P.; Hanisch, J.; Sparing, M.; Bianchetti, M.; MacManus-Driscoll, J.; Lao, M.; Eisterer, M.; Meledin, A.; Van Tendeloo, G.; et al. Ba2Y(Nb/Ta)O6-Doped YBCO Films on Biaxially Textured Ni-5at.% W Substrates. IEEE Trans. Appl. Supercond. 2016, 26, 7500305.
  61. Feldmann, D.M.; Holesinger, T.G.; Maiorov, B.; Foltyn, S.R.; Coulter, J.Y.; Apodaca, I. Improved flux pinning in YBa2Cu3O7 with nanorods of the double perovskite Ba2YNbO6. Supercond. Sci. Technol. 2010, 23, 095004.
  62. Opherden, L.; Sieger, M.; Pahlke, P.; Huhne, R.; Schultz, L.; Meledin, A.; Van Tendeloo, G.; Nast, R.; Holzapfel, B.; Bianchetti, M.; et al. Large pinning forces and matching effects in YBa2Cu3O7-δ thin films with Ba2Y(Nb/Ta)O6 nano-precipitates. Sci. Rep. 2016, 6, 21188.
  63. Wee, S.H.; Goyal, A.; Zuev, Y.L.; Cantoni, C.; Selvamanickam, V.; Specht, E.D. Formation of Self-Assembled, Double-Perovskite, Ba2YNbO6 Nanocolumns and Their Contribution to Flux-Pinning and Jc in Nb-Doped YBa2Cu3O7-d Films. Appl. Phys. Express. 2010, 3, 023101.
  64. Wee, S.H.; Zuev, Y.L.; Cantoni, C.; Goyal, A. Engineering nanocolumnar defect configurations for optimized vortex pinning in high temperature superconducting nanocomposite wires. Sci. Rep. 2013, 3, 2749.
  65. Ercolano, G.; Harrington, S.A.; Wang, H.; Tsai, C.F.; MacManus-Driscoll, J.L. Enhanced flux pinning in YBa2Cu3O7-d thin films using Nb-based double perovskite additions. Supercond. Sci. Technol. 2010, 23, 022003.
  66. Jha, A.K.; Matsumoto, K.; Horide, T.; Saini, S.; Mele, P.; Yoshida, Y.; Awaji, S. Tuning the microstructure and vortex pinning properties of YBCO-based superconducting nanocomposite films by controlling the target rotation speed. Supercond. Sci. Technol. 2014, 27, 025009.
  67. Harrington, S.A.; Durrell, J.H.; Maiorov, B.; Wang, H.; Wimbush, S.C.; Kursumovic, A.; Lee, J.H.; MacManus-Driscoll, J.L. Self-assembled, rare earth tantalate pyrochlore nanoparticles for superior flux pinning in YBa2Cu3O7-δ films. Supercond. Sci. Technol. 2009, 22, 022001.
  68. Wee, S.H.; Goyal, A.; Specht, E.D.; Cantoni, C.; Zuev, Y.L.; Selvamanickam, V.; Cook, S. Enhanced flux pinning and critical current density via incorporation of self-assembled rare-earth barium tantalate nanocolumns within YBa2Cu3O7-δ films. Phys. Rev. B 2010, 81, 140503.
  69. Tobita, H.; Notoh, K.; Higashikawa, K.; Inoue, M.; Kiss, T.; Kato, T.; Hirayama, T.; Yoshizumi, M.; Izumi, T.; Shiohara, Y. Fabrication of BaHfO3 doped Gd1Ba2Cu3O7-δ coated conductors with the high Ic of 85 A/cm-w under 3 T at liquid nitrogen temperature (77 K). Supercond. Sci. Technol. 2012, 25, 062002.
  70. Tsuruta, A.; Watanabe, S.; Ichino, Y.; Yoshida, Y. Enhancement of critical current density in the force-free sate of BaHfO3-doped multilayered SmBa2Cu3Oy film. Jpn J. Appl. Phys 2014, 53, 078003.
  71. Tsuruta, A.; Yoshida, Y.; Ichino, Y.; Ichinose, A.; Matsumoto, K.; Awaji, S. The influence of the geometric characteristics of nanorods on the flux pinning in high-performance BaMO3-doped SmBa2Cu3Oy films (M = Hf, Sn). Supercond. Sci. Technol. 2014, 27, 065001.
  72. Miura, S.; Yoshida, Y.; Ichino, Y.; Matsumoto, K.; Ichinose, A.; Awaji, S. Characteristics of high-performance BaHfO3-doped SmBa2Cu3Oy superconducting films fabricated with a seed layer and low-temperature growth. Supercond. Sci. Technol. 2015, 28, 065013.
  73. Miura, S.; Yoshida, Y.; Ichino, Y.; Tsuruta, A.; Matsumoto, K.; Ichinose, A.; Awaji, S. Flux pinning properties and microstructures of a SmBa2Cu3Oy film with high number density of BaHfO3 nanorods deposited by using low-temperature growth technique. Jpn J. Appl. Phys. 2014, 53, 090304.
  74. Awaji, S.; Yoshida, Y.; Suzuki, T.; Watanabe, K.; Hikawa, K.; Ichino, Y.; Izumi, T. High-performance irreversibility field and flux pinning force density in BaHfO3-doped GdBa2Cu3Oy tape prepared by pulsed laser deposition. Appl. Phys. Express. 2015, 8, 023101.
  75. Engel, S.; Thersleff, T.; Hühne, R.; Schultz, L.; Holzapfel, B.; Engel, S.; Thersleff, T.; Schultz, L.; Holzapfel, B.; Schultz, L. Enhanced flux pinning in YBa2Cu3O7 layers by the formation of nanosized BaHfO3 precipitates using the chemical deposition method. Appl. Phys. Lett. 2007, 90, 3.
  76. Cayado, P.; Erbe, M.; Kauffmann-Weiss, S.; Buhler, C.; Jung, A.; Hanisch, J.; Holzapfel, B. Large critical current densities and pinning forces in CSD-grown superconducting GdBa2Cu3O7-δ-BaHfO3 nanocomposite films. Supercond. Sci. Technol. 2017, 30, 094007.
  77. Crisan, A.; Dang, V.S.; Mikheenko, P. Nano-engineered pinning centres in YBCO superconducting films. Phys. C Supercond. Its Appl. 2017, 533, 118–132.
  78. Sarkar, A.; Mikheenko, P.; Dang, V.S.; Awang Kechik, M.M.; Abell, J.S.; Crisan, A. Improved Critical Current Densities in YBa2Cu3O7−δ Multilayer Films Interspaced with Palladium Nano-dots. J. Supercond. Nov. Magn. 2010, 24, 173–177.
  79. Gapud, A.A.; Kumar, D.; Viswanathan, S.K.; Cantoni, C.; Varela, M.; Abiade, J.; Pennycook, S.J.; Christen, D.K. Enhancement of flux pinning in YBa2Cu3O7-d thin films embedded with epitaxially grown Y2O3 nanostructures using a multi-layering process. Supercond. Sci. Technol. 2005, 18, 1502–1505.
  80. Cai, C.; Hanisch, J.; Huhne, R.; Stehr, V.; Mickel, C.; Gemming, T.; Holzapfel, B. Structural and magnetotransport properties of YBa2Cu3O7-δ/Y2O3 quasimultilayers. J. Appl. Phys. 2005, 98, 123906.
  81. Cai, C.B.; Zhang, J.C.; Cao, S.X.; Hänisch, J.; Hühne, R.; Holzapfel, B. Growth-controlled precipitates for flux pinning enhancement in YBa2Cu3O7−δ films and coated conductors. Phys. C Supercond. 2007, 460–462, 1355–1356.
  82. Kiessling, A.; Hanisch, J.; Thersleff, T.; Reich, E.; Weigand, M.; Huhne, R.; Sparing, M.; Holzapfel, B.; Durrell, J.H.; Schultz, L. Nanocolumns in YBa2Cu3O7-δ/BaZrO3 quasi-multilayers: Formation and influence on superconducting properties. Supercond. Sci. Technol. 2011, 24, 055018.
  83. Huhtinen, H.; Schlesier, K.; Paturi, P. Growth andc-axis flux pinning of nanostructured YBCO/BZO multilayers. Supercond. Sci. Technol. 2009, 22, 075019.
  84. Cai, C.; Liu, J.; Liu, Z.; Ying, L.; Gao, B.; Peng, L.; Chen, C. Heteroperovskite phase formation and magnetotransport properties of YBa2Cu3O7−x/SrRuO3 quasimultilayers. J. Appl. Phys. 2008, 104, 023913.
  85. Petrov, P.K.; Ivanov, Z.G.; Gevorgyan, S.S. X-ray study of SrTiO3 thin films in multilayer structures. Mater. Sci. Eng. A 2000, 288, 231–234.
  86. Mukaida, M.; Miyazawa, S. In-plane alignment ofa-axis oriented YBa2Cu3Ox thin films. Appl. Phys. Lett. 1993, 63, 999–1001.
  87. Peng, L.; Cai, C.; Chen, C.; Liu, Z.; Hühne, R.; Holzapfel, B. Angular-dependent vortex pinning mechanism in YBa2Cu3O7−δ/YSZ quasi-multilayer. J. Appl. Phys. 2008, 104, 033920.
  88. Haugan, T.; Barnes, P.N.; Maartense, I.; Cobb, C.B.; Lee, E.J.; Sumption, M. Island growth of Y2BaCuO5 nanoparticles in (211∼1.5 nm/123∼10 nm)×N composite multilayer structures to enhance flux pinning of YBa2Cu3O7−δ films. J. Mater. Res. 2011, 18, 2618–2623.
  89. Crisan, A.; Dang, V.S.; Mikheenko, P.; Tse, Y.Y.; Sarkar, A.; Bowen, J.; Abell, J.S. Pinning potential in thick PrBa2Cu3Ox/YBa2Cu3O7−δ quasi-multilayers. Phys. C Supercond. 2010, 470, 55–60.
  90. Hanisch, J.; Cai, C.; Huhne, R.; Schultz, L.; Holzapfel, B. Formation of nanosized BaIrO3 precipitates and their contribution to flux pinning in Ir-doped YBa2Cu3O7-δ quasi-multilayers. Appl. Phys. Lett. 2005, 86, 122508.
  91. Hanisch, J.; Cai, C.; Stehr, V.; Huhne, R.; Lyubina, J.; Nenkov, K.; Fuchs, G.; Schultz, L.; Holzapfel, B. Formation and pinning properties of growth-controlled nanoscale precipitates in YBa2Cu3O7−δ/transition metal quasi-multilayers. Supercond. Sci. Technol. 2006, 19, 534–540.
  92. Maiorov, B.; Baily, S.A.; Zhou, H.; Ugurlu, O.; Kennison, J.A.; Dowden, P.C.; Holesinger, T.G.; Foltyn, S.R.; Civale, L. Synergetic combination of different types of defect to optimize pinning landscape using BaZrO3-doped YBa2Cu3O7. Nat. Mater. 2009, 8, 398–404.
  93. Mele, P.; Matsumoto, K.; Horide, T.; Ichinose, A.; Mukaida, M.; Yoshida, Y.; Horii, S.; Kita, R. Incorporation of double artificial pinning centers in YBa2Cu3O7-δ films. Supercond. Sci. Technol. 2008, 21, 015019.
  94. Ding, F.Z.; Gu, H.W.; Zhang, T.; Wang, H.Y.; Qu, F.; Dai, S.T.; Peng, X.Y.; Cao, J.L. Enhanced flux pinning in MOD-YBCO films with co-doping of BaZrO3 and Y2O3 nanoparticles. J. Alloy Compd. 2012, 513, 277–281.
  95. Jha, A.K.; Matsumoto, K.; Horide, T.; Saini, S.; Mele, P.; Ichinose, A.; Yoshida, Y.; Awaji, S. Controlling the critical current anisotropy of YBCO superconducting films by incorporating hybrid artificial pinning centers. IEEE Trans. Appl. Supercond. 2016, 26, 8000404.
  96. Jha, A.K.; Matsumoto, K.; Horide, T.; Saini, S.; Mele, P.; Yoshida, Y.; Awaji, S. Systematic variation of hybrid APCs Into YBCO thin films for improving the vortex pinning properties. IEEE Trans. Appl. Supercond. 2015, 25, 8000505.
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