Reproducible technique for fabrication of thin films of high transition temperature superconductors

Mankiewich, P. M.; Scofield, John; Skocpol, W. J.; Howard, R. E.; Dayem, A. H.; Good, E.

doi:10.1063/1.98513

Cited by 416 publications

(59 citation statements)

References 7 publications

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“…4 The method yields high-quality c-axis perpendicular films with 10-//m grains, critical current density ^:2xl0 6 A cm ~2 at 77 K, and a-b -plane resistivity of 400 /iftcmat 295 K. We found the penetration-depth measurement itself to be a sensitive and critical test of film quality.…”

Section: Renormalization Of the Mean-field Superconducting Penetratiomentioning

confidence: 96%

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
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The a-b-plane penetration depth X(T) in YBa2Cu3C>7 films, determined from kinetic inductance measurements, follows the temperature dependence of weak-coupling mean-field BCS theory near T c to within ~0.5 K of T c , resolution limited either by homogeneity or for the thinnest films by phase fluctuations. The Kosterlitz-Thouless transition in a thin film is the first observation in a clean type-II superconductor, noted by the universal superfluid jump and the algebraic-decay law with a square-root cusp exponent.A kinetic inductance method in which supercurrent flow is induced in the a-b basal plane of oaxis-oriented epitaxial YBa2Cu3C>7 films grown on SrTiChOOO) was used to measure the weak-field in-plane component of the penetration depth X. [ Properties of the high-r c cuprates such as the short coherence length £o, comparatively long mean free path /, large a-b vs c anisotropy, superconducting energy gap A(T), together with thermodynamic fluctuations near T c will influence the detailed temperature dependence of X(T), which is a measure of the superelectron density and of the observed dissipation, which is associated with vortex motion. For temperatures not too close to T c , the weak-coupling mean-field BCS theory with A/&r c = 1.76 and X(0)=0.15 /im provides a good fit to X(T) in films with the sharpest transitions. Broadening by film inhomogeneity correlates with a systematic increase in the magnitude of X(T). Phase fluctuations driven by the presence of quantized vortices are clearly observed in 500-A films, where the entire film fluctuates as a two-dimensional (2D) superconductor. The data presented here are the first to show the Kosterlitz-Thouless (KT) transition 2 in an intrinsic (/ > £o) type-II superconductor, as distinct from the earlier restriction to high-resistivity dirty-limit oxides. 3 The intriguing possibility of renormalization by 2D fluctuations within the CuC>2 planes is consistent with the data.Various films from 500 to 2000 A thick were prepared by coevaporation from Cu, Y, and BaF2 sources onto polished SrTiO 3 (100) and by reaction at 800 °C in 0 2 with water vapor used to catalyze oxidation. 4 The method yields high-quality c-axis perpendicular films with 10-//m grains, critical current density ^:2xl0 6 A cm ~2 at 77 K, and a-b -plane resistivity of 400 /iftcmat 295 K. We found the penetration-depth measurement itself to be a sensitive and critical test of film quality.The penetration depth X was calculated from a measurement of the complex ac sheet impedance of the film, Z~R + icoL. 1 Under conditions of low dissipation, the sheet kinetic inductance of the superconducting state dominates, and is given by L =4KC ~2d ~lX 2 , where d is the film thickness. The London equation may be inadequate very close to 7 C , because of fluctuations, the finite transition width, and the appearance of the dissipative component R. Applied perpendicular magnetic fields enhance L (and X) and contribute to R.The apparatus contained astatically wound 1-mmdiam drive and receive coils positioned with a 1.5-m...

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Section: Renormalization Of the Mean-field Superconducting Penetratiomentioning

confidence: 96%

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
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“…[61,62] Many of these CSD processes have been developed for depositing YBCO films. [25,63] [20,64] During pyrolysis of the MOD films, the thermodynamically stable BaF 2 phase is formed rather than BaCO 3 , which is difficult to convert to the BaO needed in the reaction to form YBCO. In both the MOD-or PVD-BaF 2 processes, the BaF 2 is effectively converted to BaO at higher temperatures by reaction with H 2 O that leads to the release of HF.…”

Section: Mod Ybco Coated Conductorsmentioning

confidence: 99%

Progress in Nanoengineered Microstructures for Tunable High‐Current, High‐Temperature Superconducting Wires

et al. 2008

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High critical current densities (Jc) in thick films of the Y1Ba2Cu3O7–δ (YBCO, Tc ≈ 92 K) superconductor directly depend upon the types of nanoscale defects and their densities within the films. A major challenge for developing a viable wire technology is to introduce nanoscale defect structures into the YBCO grains of the thick film suitable for flux pinning and the tailoring of the superconducting properties to specific, application‐dependent, temperature and magnetic field conditions. Concurrently, the YBCO film needs to be integrated into a macroscopically defect‐free conductor in which the grain‐to‐grain connectivity maintains levels of inter‐grain Jc that are comparable to the intra‐grain Jc. That is, high critical current (Ic) YBCO coated conductors must contain engineered inhomogeneities on the nanoscale, while being homogeneous on the macroscale. An analysis is presented of the advances in high‐performance YBCO coated‐conductors using chemical solution deposition (CSD) based on metal trifluoroacetates and the subsequent processing to nano‐engineer the microstructure for tuneable superconducting wires. Multi‐scale structural, chemical, and electrical investigations of the CSD film processes, thick film development, key microstructural features, and wire properties are presented. Prospects for further development of much higher Ic wires for large‐scale, commercial application are discussed within the context of these recent advances.

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“…14 The use of water vapor in this process precludes the use of either YSZ or MgO as the growth template for YBCO, both of which degrade rapidly in the presence of water vapor at the required 700°C-800°C processing temperatures. Instead, we use 4% Nb-doped SrTiO 3 ͑Nb:STO͒, which grows biaxially oriented onto Ni͑100͒ tapes from a sol-gel deposition.…”

mentioning

confidence: 99%

All solution-chemistry approach for YBa2Cu3O7−δ-coated conductors

Siegal

Clem

Dawley

et al. 2002

Applied Physics Letters

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A need exists for low-cost coated-conductor fabrication methods for applications in magnet and electric-power technologies. We demonstrate high-critical current density (Jc) YBa2Cu3O7−δ (YBCO) films grown on Nb-doped SrTiO3 (Nb:STO) buffered Ni(100) tapes. All buffer and superconductor layers are deposited using solution chemistry. A 50 nm thick Nb:STO seed layer on Ni(100) acts as a template for the growth of subsequent thicker layers of Nb:STO. Nb doping improves the electrical conductivity and oxygen diffusion barrier properties of STO. YBCO grows heteroepitaxially directly on this buffer layer, resulting in a transport Jc(77 K)=1.3 MA/cm2.

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Reproducible technique for fabrication of thin films of high transition temperature superconductors

Cited by 416 publications

References 7 publications

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
View full text Add to dashboard Cite

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
View full text Add to dashboard Cite

Progress in Nanoengineered Microstructures for Tunable High‐Current, High‐Temperature Superconducting Wires

All solution-chemistry approach for YBa2Cu3O7−δ-coated conductors

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Reproducible technique for fabrication of thin films of high transition temperature superconductors

Cited by 416 publications

References 7 publications

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3Fiory1, Hebard2, Mankiewich3 et al. 1988Phys. Rev. Lett.Self Cite2833462View full textAdd to dashboardCite

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3Fiory1, Hebard2, Mankiewich3 et al. 1988Phys. Rev. Lett.Self Cite2833462View full textAdd to dashboardCite

Progress in Nanoengineered Microstructures for Tunable High‐Current, High‐Temperature Superconducting Wires

All solution-chemistry approach for YBa2Cu3O7−δ-coated conductors

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Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
View full text Add to dashboard Cite

Renormalization of the Mean-Field Superconducting Penetration Depth in Epitaxial YBa2Cu3
Fiory
¹
,
Hebard
²
,
Mankiewich
³

et al. 1988
Phys. Rev. Lett.
Self Cite
283
3
46
2
View full text Add to dashboard Cite