Microstructure and pinning in high-Tc and large-Jc (Nd, Eu, Gd)-123 superconductors prepared by OCMG process

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Abstract

The effects of (Nd, Eu, Gd)2BaCuO5 (NEG-211), Pt and CeO2 additions on OCMG-processed (Nd, Eu, Gd)Ba2Cu3Oy ('NEG') composites have been investigated in detail using a combination of scanning electron microscopy and measurements of critical current densities, Jc. Microstructural observations clearly indicated that the platinum addition was effective in refining the NEG-211 secondary-phase particles, which led to a dramatic increase in Jc in the low-field as well as in the high-field region. TEM-EDX analyses revealed that the small secondary-phase particles (diameter ≈0.1 μm) consist mainly of Gd in the rare earth site, while the large particles contain Nd, Eu and Gd in the rare earth site with an even ratio, which is identical to the nominal composition of the precursor powder. For an NEG sample with 40 mol% NEG-211 additions, a large critical current density of 60000 A cm-2 at 77 K was observed in a magnetic field of 3 T applied parallel to the c-axis of the sample. The critical current density measurements showed that the zero field and peak Jc values are similar in samples with 30 and 40 mol% of NEG-211 added. In contrast to this, the combination of CeO2 and Pt addition was not as effective in refining the NEG-211 particles, and also the Jc values were found to decrease in the entire field region.

Original languageEnglish
Pages (from-to)1349-1358
Number of pages10
JournalSuperconductor Science and Technology
Volume11
Issue number12
DOIs
Publication statusPublished - 1998 Dec
Externally publishedYes

Fingerprint

Rare earths
Superconducting materials
Refining
critical current
microstructure
Microstructure
refining
Electric current measurement
current density
Platinum
Powders
Energy dispersive spectroscopy
rare earth elements
Magnetic fields
Transmission electron microscopy
Scanning electron microscopy
Composite materials
Chemical analysis
platinum
transmission electron microscopy

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

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title = "Microstructure and pinning in high-Tc and large-Jc (Nd, Eu, Gd)-123 superconductors prepared by OCMG process",
abstract = "The effects of (Nd, Eu, Gd)2BaCuO5 (NEG-211), Pt and CeO2 additions on OCMG-processed (Nd, Eu, Gd)Ba2Cu3Oy ('NEG') composites have been investigated in detail using a combination of scanning electron microscopy and measurements of critical current densities, Jc. Microstructural observations clearly indicated that the platinum addition was effective in refining the NEG-211 secondary-phase particles, which led to a dramatic increase in Jc in the low-field as well as in the high-field region. TEM-EDX analyses revealed that the small secondary-phase particles (diameter ≈0.1 μm) consist mainly of Gd in the rare earth site, while the large particles contain Nd, Eu and Gd in the rare earth site with an even ratio, which is identical to the nominal composition of the precursor powder. For an NEG sample with 40 mol{\%} NEG-211 additions, a large critical current density of 60000 A cm-2 at 77 K was observed in a magnetic field of 3 T applied parallel to the c-axis of the sample. The critical current density measurements showed that the zero field and peak Jc values are similar in samples with 30 and 40 mol{\%} of NEG-211 added. In contrast to this, the combination of CeO2 and Pt addition was not as effective in refining the NEG-211 particles, and also the Jc values were found to decrease in the entire field region.",
author = "Muralidhar Miryala and Koblischka, {Michael Rudolf} and T. Saitoh and Masato Murakami",
year = "1998",
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T1 - Microstructure and pinning in high-Tc and large-Jc (Nd, Eu, Gd)-123 superconductors prepared by OCMG process

AU - Miryala, Muralidhar

AU - Koblischka, Michael Rudolf

AU - Saitoh, T.

AU - Murakami, Masato

PY - 1998/12

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N2 - The effects of (Nd, Eu, Gd)2BaCuO5 (NEG-211), Pt and CeO2 additions on OCMG-processed (Nd, Eu, Gd)Ba2Cu3Oy ('NEG') composites have been investigated in detail using a combination of scanning electron microscopy and measurements of critical current densities, Jc. Microstructural observations clearly indicated that the platinum addition was effective in refining the NEG-211 secondary-phase particles, which led to a dramatic increase in Jc in the low-field as well as in the high-field region. TEM-EDX analyses revealed that the small secondary-phase particles (diameter ≈0.1 μm) consist mainly of Gd in the rare earth site, while the large particles contain Nd, Eu and Gd in the rare earth site with an even ratio, which is identical to the nominal composition of the precursor powder. For an NEG sample with 40 mol% NEG-211 additions, a large critical current density of 60000 A cm-2 at 77 K was observed in a magnetic field of 3 T applied parallel to the c-axis of the sample. The critical current density measurements showed that the zero field and peak Jc values are similar in samples with 30 and 40 mol% of NEG-211 added. In contrast to this, the combination of CeO2 and Pt addition was not as effective in refining the NEG-211 particles, and also the Jc values were found to decrease in the entire field region.

AB - The effects of (Nd, Eu, Gd)2BaCuO5 (NEG-211), Pt and CeO2 additions on OCMG-processed (Nd, Eu, Gd)Ba2Cu3Oy ('NEG') composites have been investigated in detail using a combination of scanning electron microscopy and measurements of critical current densities, Jc. Microstructural observations clearly indicated that the platinum addition was effective in refining the NEG-211 secondary-phase particles, which led to a dramatic increase in Jc in the low-field as well as in the high-field region. TEM-EDX analyses revealed that the small secondary-phase particles (diameter ≈0.1 μm) consist mainly of Gd in the rare earth site, while the large particles contain Nd, Eu and Gd in the rare earth site with an even ratio, which is identical to the nominal composition of the precursor powder. For an NEG sample with 40 mol% NEG-211 additions, a large critical current density of 60000 A cm-2 at 77 K was observed in a magnetic field of 3 T applied parallel to the c-axis of the sample. The critical current density measurements showed that the zero field and peak Jc values are similar in samples with 30 and 40 mol% of NEG-211 added. In contrast to this, the combination of CeO2 and Pt addition was not as effective in refining the NEG-211 particles, and also the Jc values were found to decrease in the entire field region.

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