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Title: YBCO Coated Conductors

 [1];  [1];  [2];  [2];  [1]
  1. ORNL
  2. Los Alamos National Laboratory (LANL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
DOE Contract Number:
Resource Type:
Country of Publication:
United States

Citation Formats

Paranthaman, Mariappan Parans, Aytug, Tolga, Stan, Liliana, Jia, Quanxi, and Cantoni, Claudia. YBCO Coated Conductors. United States: N. p., 2015. Web.
Paranthaman, Mariappan Parans, Aytug, Tolga, Stan, Liliana, Jia, Quanxi, & Cantoni, Claudia. YBCO Coated Conductors. United States.
Paranthaman, Mariappan Parans, Aytug, Tolga, Stan, Liliana, Jia, Quanxi, and Cantoni, Claudia. 2015. "YBCO Coated Conductors". United States. doi:.
title = {YBCO Coated Conductors},
author = {Paranthaman, Mariappan Parans and Aytug, Tolga and Stan, Liliana and Jia, Quanxi and Cantoni, Claudia},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2015,
month = 1

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  • Since the discovery of high-temperature superconductors (HTS) in 1986, both (Bi,Pb)2Sr2Ca2Cu3O10 (BSCCO or 2223 with a critical temperature, Tc of 110 K) and YBa2Cu3O7- (YBCO or 123 with a Tc of 91 K) have emerged as the leading candidate materials for the first generation (1G) and second generation (2G) high temperature superconductor wires or tapes that will carry high critical current density in liquid nitrogen temperatures [1-7]. The crystal structures and detailed fundamental properties of BSCCO and YBCO superconductors have been reviewed by Matsumoto in a separate chapter in this book. The U.S. Department of Energy s target price formore » the conductor is close to the current copper wire cost of $10-50/kA-meter, i.e. a meter of copper type conductor carrying 1000 A current costs ~ $ 50 [8]. The long-term goal for the DOE, Office of Electricity, Advanced Conductors and Cables program is to achieve HTS wire in 1000 meters long with current carrying capacity of 1000 A/cm [8]. Robust, high-performance HTS wire will certainly revolutionize the electric power grid and various other electric power equipments as well. Sumitomo Electric Power (Japan) has been widely recognized as the world leader in manufacturing the first-generation HTS wires based on BSCCO materials using the Oxide-Powder-In-Tube (OPIT) over-pressure process [9]. Typically, 1G HTS wires carry critical currents, Ic, of over 200 Amperes (A) in piece lengths of one kilometer lengths at the standard 4 mm width and ~ 200 m thickness. However, due to the higher cost of 1G wire, mainly because of the cost of Ag alloy sheath, the researchers shifted their effort towards the development of YBCO (second generation 2G) tapes in the last fifteen years [1-7]. One of the main obstacles to the ability to carry high critical currents in YBCO films has been the phenomenon of weak links, i.e., grain boundaries formed by the misalignment of neighboring YBCO grains are known to form obstacles to current flow [10]. By carefully aligning the grains in YBCO films, low angle boundaries between superconducting YBCO grains allow more current to flow. In fact below a critical misalignment angle of 4 , the critical current density approaches that of YBCO films grown on single crystal substrates [10]. Typically, 2G HTS wires have three components, flexible metal substrate, buffer layers, and REBa2Cu3O7- (REBCO: RE = Rare Earth) superconductor layers [1-7]. Several methods were developed to obtain biaxially textured templates suitable for fabricating high-performance YBCO coated conductors. They are Ion-Beam Assisted Deposition (IBAD), Rolling-Assisted Biaxially Textured Substrates (RABiTS) and Inclined-Substrate Deposition (ISD). Compared to 1G wire, for producing 2G wires using RABiTS or IBAD process, silver is replaced by a low cost nickel alloy, which allows for fabrication of less expensive HTS wires.« less
  • We have reviewed briefly the growth of buffer and high temperature superconducting oxide thin films using a chemical solution deposition (CSD) method. In the Rolling-Assisted Biaxially Textured Substrates (RABiTS) process, developed at Oak Ridge National Laboratory, utilizes the thermo mechanical processing to obtain the flexible, biaxially oriented copper, nickel or nickel-alloy substrates. Buffers and Rare Earth Barium Copper Oxide (REBCO) superconductors have been deposited epitaxially on the textured nickel alloy substrates. The starting substrate serves as a template for the REBCO layer, which has substantially fewer weak links. Buffer layers play a major role in fabricating the second generation REBCOmore » wire technology. The main purpose of the buffer layers is to provide a smooth, continuous and chemically inert surface for the growth of the REBCO film, while transferring the texture from the substrate to the superconductor layer. To achieve this, the buffer layers need to be epitaxial to the substrate, i.e. they have to nucleate and grow in the same bi-axial texture provided by the textured metal foil. The most commonly used RABiTS multi-layer architectures consist of a starting template of biaxially textured Ni-5 at.% W (Ni-W) substrate with a seed (first) layer of Yttrium Oxide (Y2O3), a barrier (second) layer of Yttria Stabilized Zirconia (YSZ), and a Cerium Oxide (CeO2) cap (third) layer. These three buffer layers are generally deposited using physical vapor deposition (PVD) techniques such as reactive sputtering. On top of the PVD template, REBCO film is then grown by a chemical solution deposition. This article reviews in detail about the list of oxide buffers and superconductor REBCO films grown epitaxially on single crystal and/or biaxially textured Ni-W substrates using a CSD method.« less
  • Although the first epitaxial films of YBCO with high Tc were grown nearly 20 years ago, the understanding and control of the nanostructures responsible for the dissipation-free electrical current transport in high temperature superconductors (HTS) is quite recent. In the last six to seven years, major advances have occurred in the fundamental investigation of low angle grain boundaries, flux-pinning phenomena, growth mode, and atomic-level defect structures of HTS epitaxial films. As a consequence, it has been possible to map and even engineer to some extent the performance of HTS coatings in large regions of the operating H, T, J phasemore » space. With such progress, the future of high temperature superconducting wires looks increasingly promising despite the tremendous challenges offered by these brittle and anisotropic materials. Nevertheless, further performance improvements are necessary for the superconducting technology to become cost-competitive against copper wires and ultimately succeed in revolutionizing the transmission of electricity. This can be achieved by further diminishing the gap between theoretical and experimental values of the critical current density Jc, and/or increasing the thickness of the superconductive layer as much as possible without degrading performance. In addition, further progress in controlling extrinsic and/or intrinsic nano-sized defects within the films is necessary to significantly reduce the anisotropic response of HTS and obtain a nearly constant dependence of the critical current on the magnetic field orientation, which is considered crucial for power applications. This chapter is a review of the challenges still present in the area of superconducting film processing for HTS wires and the approaches currently employed to address them.« less
  • In continuation of our effort to develop single buffer layer architectures for YBCO (YBa 2Cu 3O 7-g) coated tape conductors, we have studied RE2O3 (RE = Y, and rare earths) as candidate materials. Three types of crystal structures including the preferred cubic phase are known for the rare earth oxides. High quality simple cubic RE2O3 buffer layers were grown epitaxiahy on {100}<001> textured Ni substrates using both reactive evaporation and sol-gel processing. Detailed X-ray studies have shown that the Y2O3, Eu2O3, Gd2O3, and Yb2O3 were grown with a single epitaxial orientation. SEM micrographs indicated that both e-beam and sol-gel grownmore » films were dense, continuous and crack free. High Jc YBCO films were grown on RE2O3-buffered Ni substrates with sputtered cap layers. Two new alternative buffer layer architectures were developed. A high Jc of 1.8 MA/cm2 at 77 K and self-field was obtained on YBCO films with a layer sequence of YBCO (pulsed laser deposition)/Yb2O3 (sputtered)/Y2O3 (e-beam)/Ni. Also, a high Jc of over 1 MA/cm2 at 77 K and self-field was obtained on YBCO films with a layer sequence of YBCO (ex-situ BaF2 process)/CeO2 (sputtered)YSZ sputtered)/RE2O3 (sol-gel or e-beam)Ni. The performance of sol-gel grown buffers approached the quality of e-beam grown buffers.« less
  • Continuous coaters capable of producing 1.1 m long x 1 cm wide tapes of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) on biaxially oriented yttria-stabilized zirconia (YSZ) on flexible Ni-alloy substrates have been developed at this laboratory. Using a 1 {micro}V/cm criterion, the authors have achieved transport critical current (I{sub c}) values of 29 A (75 K, self field) between voltage taps spaced 1 m apart. The corresponding critical current density (J{sub c}) value for this tape is 290 kA/cm{sup 2}. For shorter tapes, (12 cm voltage tap separation) they have attained J{sub c} values of 0.67 MA/cm{sup 2}. Individual 1 xmore » 1 cm sections within these shorter tapes have attained J{sub c} values of 1 MA/cm{sup 2}.« less