Calcining conditions for YBa/sub 2/Cu/sub 3/O/sub 7-x/ films by metalorganic deposition using trifluoroacetates

Niwa, T.; Araki, Takao; Muroga, T.; Iijima, Y.; Yamada, Yutaka; Saitoh, Takashi; Hirabayashi, I.; Shiohara, Yuh

doi:10.1109/tasc.2003.811987

Cited by 7 publications

(3 citation statements)

References 17 publications

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“…Unfortunately, the TFA route to YBCO films has until now required a double step process (pyrolysis and growth) and for a long time the microstructural evolution during the pyrolysis process has remained highly obscure. As a consequence, very long (∼24 h) non-optimized thermal processes were initially believed to be necessary to preserve the film quality [18,57,72]. However, after much progress in understanding the MO decomposition process, it is now possible to achieve high-quality films using much shorter pyrolysis steps (<30 min) [56,61,64].…”

Section: Pyrolysismentioning

confidence: 99%

Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions

Obradors¹,

Puig²,

Ricart³

et al. 2012

Supercond. Sci. Technol.

172

235

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Chemical solution deposition (CSD) is a very competitive technique to obtain epitaxial films and multilayers of high quality with controlled nanostructures. Based on the strong attractiveness from the cost point of view, the production of long length coated conductors based on the CSD approach is being extensively developed. The trifluoroacetate route (TFA) is the most widely used route to achieve epitaxial YBa 2 Cu 3 O 7 (YBCO) layers with high critical currents, however a deep understanding of all the individual consecutive processing steps, as well as their mutual influence and relationship, is required to achieve superconducting materials with high performance. In this work, we review advances in the knowledge of all the steps relevant to the preparation of YBCO thin films based on TFA precursors as a CSD methodology: solution preparation and deposition, pyrolysis processes, intermediate phase evolution, nucleation and growth phenomena, microstructural evolution and its influence on percolating supercurrents, as well as vortex pinning by natural existing defects. Finally, we discuss the open issues still existing in the TFA approach, particularly that of film nanostructuration, and we provide a future outlook for this outstanding methodology.

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Section: Pyrolysismentioning

confidence: 99%

Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions

Obradors¹,

Puig²,

Ricart³

et al. 2012

Supercond. Sci. Technol.

172

235

View full text Add to dashboard Cite

show abstract

“…The calcining conditions for the formation of YBCO films by metallorganic deposition using trifluoroacetates have been discussed by Niwa and colleagues. 225 As well as the residual C content being determined by SIMS, the authors also measured the critical current density (J (c) ) of the films calcined at different temperatures. The J (c) values of the films depended on decomposition of the trifluoroacetates and copper oxide nanocrystallite growth rather than the influence of the C content.…”

Section: Semiconductors and Conducting Materialsmentioning

confidence: 99%

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

Fisher

Goodall

Hinds

et al. 2004

J. Anal. At. Spectrom.

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“…YBCO coated conductors have been characterised by a number of research groups and the effect of the synthesis procedure, such as the choice of precursors [25,28,29], the decomposition [29][30][31][32][33][34][35] and reaction [36][37][38] conditions have been widely studied.…”

Section: Ybco Coated Conductorsmentioning

confidence: 99%

Electron Microscopy Imaging of Flux Pinning Defects in YBCO Superconductors

Puichaud¹

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<p>High-temperature superconductors are of great interest because they can transport electrical current without loss. For real-world applications, the amount of current, known as the critical current Ic, that can be carried by superconducting wires is the key figure of merit. Large Ic values are necessary to off-set the higher cost of these wires. The factors that improve Ic (microstructure/performance relationship) in the state-of-the-art coated conductor wires based on YBa₂Cu₃O₇ (YBCO) are not fully understood. However, microstructural defects that immobilise (or pin) tubes of magnetic flux (known as vortices) inside the coated conductors are known to play a role in improving Ic. In this thesis, the vortex-defect interaction in YBCO superconductors was investigated with high-end transmission electron microscopy (TEM) techniques using two approaches. First, the effect of dysprosium (Dy) addition and oxygenation temperature on the microstructure and critical current were investigated in detail. Changing only the oxygenation temperature leads to many microstructural changes in pure YBCO coated conductors. It was found that Dy addition reduces the sensitivity of the YBCO to the oxygenation temperature, in particular it lowers the microstructural disorder while maintaining the formation of nanoparticles, which both contribute to the enhancement of Ic. In the second approach, two TEM based techniques (off-axis electron holography and Lorentz microscopy) were used to study the magnetic flux vortices. Vortex imaging was attempted with a TEM operated at 300 kV on both a YBCO crystal as well as a YBCO coated conductor. Many challenges were encountered including sample preparation, inhomogeneity, and geometry, in addition to the need to perform measurements at cryogenic temperatures. Although vortices were not able to be observed in the coated conductors, tentative observation of vortices in a YBCO crystal was made using Lorentz microscopy. Improvements for future electron holography experiments on YBCO at low voltage are suggested. This work represents a pioneering step towards directly imaging vortices in YBCO using more widely available microscopes with the aim of better understanding flux pinning to ultimately boost Ic in superconducting wires.</p>

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Calcining conditions for YBa/sub 2/Cu/sub 3/O/sub 7-x/ films by metalorganic deposition using trifluoroacetates

Cited by 7 publications

References 17 publications

Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions

Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

Electron Microscopy Imaging of Flux Pinning Defects in YBCO Superconductors

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Calcining conditions for YBa/sub 2/Cu/sub 3/O/sub 7-x/ films by metalorganic deposition using trifluoroacetates

Cited by 7 publications

References 17 publications

Growth, nanostructure and vortex pinning in superconducting YBa2Cu3O7thin films based on trifluoroacetate solutions

Growth, nanostructure and vortex pinning in superconducting YBa2Cu3O7thin films based on trifluoroacetate solutions

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

Electron Microscopy Imaging of Flux Pinning Defects in YBCO Superconductors

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Product

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Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions

Growth, nanostructure and vortex pinning in superconducting YBa₂Cu₃O₇thin films based on trifluoroacetate solutions