Refinement of secondary phase particles for high critical current densities in (Nd,Eu,Gd)-Ba-Cu-O superconductors

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Abstract

We have prepared (Nd0.33Eu0.33Gd0.33)Ba2Cu 3Oy ('NEG') superconductors by means of melt-processing under a partial oxygen pressure of 0.1%. In these samples, we achieved a large critical current density, Jc, of 6.8 × 104 A/cm2 at T = 77 K and in an applied magnetic field, Ha = 2.5 T. Furthermore, the irreversibility field, Hirr, exceeds 7 T at 77 K for fields applied parallel to the c-axis of the sample. As additional pinning sites, we introduced up to 40 mol% (Nd,Eu,Gd)2BaCuO5 (NEG-211) particles plus Pt in analogy to YBa2Cu3Oy (YBCO) melt-processed superconductors. Microstructural observations clarified that the Pt addition was effective in reducing the size of NEG-211 second-phase particles, which led to a dramatic increase in Jc as compared to melt-processed YBa2Cu3Oy and NdBa2Cu3Oy (NdBCO). A pronounced secondary peak effect was observed in all magnetization curves obtained at 77 K, however, there is a considerable change in the shape of the magnetization loops as a function of NEG-211 content, which demonstrates the pinning provided by the NEG-211 particles in addition to the δTc-pinning caused by fluctuation in the transition temperature, Tc, like in ordinary NdBa2Cu3Oy superconductors.

Original languageEnglish
Pages (from-to)232-240
Number of pages9
JournalPhysica C: Superconductivity and its Applications
Volume313
Issue number3-4
Publication statusPublished - 1999 Feb 20
Externally publishedYes

Fingerprint

Superconducting materials
critical current
current density
Magnetization
magnetization
Superconducting transition temperature
transition temperature
Magnetic fields
Oxygen
oxygen
curves
Processing
magnetic fields

Keywords

  • (Nd,Eu,Gd)BaCuO
  • (Nd,Eu,Gd)BaCuO
  • Critical current density
  • Flux pinning
  • Melt processing
  • Microstructure
  • Peak effect
  • Pt addition

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

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title = "Refinement of secondary phase particles for high critical current densities in (Nd,Eu,Gd)-Ba-Cu-O superconductors",
abstract = "We have prepared (Nd0.33Eu0.33Gd0.33)Ba2Cu 3Oy ('NEG') superconductors by means of melt-processing under a partial oxygen pressure of 0.1{\%}. In these samples, we achieved a large critical current density, Jc, of 6.8 × 104 A/cm2 at T = 77 K and in an applied magnetic field, Ha = 2.5 T. Furthermore, the irreversibility field, Hirr, exceeds 7 T at 77 K for fields applied parallel to the c-axis of the sample. As additional pinning sites, we introduced up to 40 mol{\%} (Nd,Eu,Gd)2BaCuO5 (NEG-211) particles plus Pt in analogy to YBa2Cu3Oy (YBCO) melt-processed superconductors. Microstructural observations clarified that the Pt addition was effective in reducing the size of NEG-211 second-phase particles, which led to a dramatic increase in Jc as compared to melt-processed YBa2Cu3Oy and NdBa2Cu3Oy (NdBCO). A pronounced secondary peak effect was observed in all magnetization curves obtained at 77 K, however, there is a considerable change in the shape of the magnetization loops as a function of NEG-211 content, which demonstrates the pinning provided by the NEG-211 particles in addition to the δTc-pinning caused by fluctuation in the transition temperature, Tc, like in ordinary NdBa2Cu3Oy superconductors.",
keywords = "(Nd,Eu,Gd)BaCuO, (Nd,Eu,Gd)BaCuO, Critical current density, Flux pinning, Melt processing, Microstructure, Peak effect, Pt addition",
author = "Muralidhar Miryala and Koblischka, {Michael Rudolf} and Masato Murakami",
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TY - JOUR

T1 - Refinement of secondary phase particles for high critical current densities in (Nd,Eu,Gd)-Ba-Cu-O superconductors

AU - Miryala, Muralidhar

AU - Koblischka, Michael Rudolf

AU - Murakami, Masato

PY - 1999/2/20

Y1 - 1999/2/20

N2 - We have prepared (Nd0.33Eu0.33Gd0.33)Ba2Cu 3Oy ('NEG') superconductors by means of melt-processing under a partial oxygen pressure of 0.1%. In these samples, we achieved a large critical current density, Jc, of 6.8 × 104 A/cm2 at T = 77 K and in an applied magnetic field, Ha = 2.5 T. Furthermore, the irreversibility field, Hirr, exceeds 7 T at 77 K for fields applied parallel to the c-axis of the sample. As additional pinning sites, we introduced up to 40 mol% (Nd,Eu,Gd)2BaCuO5 (NEG-211) particles plus Pt in analogy to YBa2Cu3Oy (YBCO) melt-processed superconductors. Microstructural observations clarified that the Pt addition was effective in reducing the size of NEG-211 second-phase particles, which led to a dramatic increase in Jc as compared to melt-processed YBa2Cu3Oy and NdBa2Cu3Oy (NdBCO). A pronounced secondary peak effect was observed in all magnetization curves obtained at 77 K, however, there is a considerable change in the shape of the magnetization loops as a function of NEG-211 content, which demonstrates the pinning provided by the NEG-211 particles in addition to the δTc-pinning caused by fluctuation in the transition temperature, Tc, like in ordinary NdBa2Cu3Oy superconductors.

AB - We have prepared (Nd0.33Eu0.33Gd0.33)Ba2Cu 3Oy ('NEG') superconductors by means of melt-processing under a partial oxygen pressure of 0.1%. In these samples, we achieved a large critical current density, Jc, of 6.8 × 104 A/cm2 at T = 77 K and in an applied magnetic field, Ha = 2.5 T. Furthermore, the irreversibility field, Hirr, exceeds 7 T at 77 K for fields applied parallel to the c-axis of the sample. As additional pinning sites, we introduced up to 40 mol% (Nd,Eu,Gd)2BaCuO5 (NEG-211) particles plus Pt in analogy to YBa2Cu3Oy (YBCO) melt-processed superconductors. Microstructural observations clarified that the Pt addition was effective in reducing the size of NEG-211 second-phase particles, which led to a dramatic increase in Jc as compared to melt-processed YBa2Cu3Oy and NdBa2Cu3Oy (NdBCO). A pronounced secondary peak effect was observed in all magnetization curves obtained at 77 K, however, there is a considerable change in the shape of the magnetization loops as a function of NEG-211 content, which demonstrates the pinning provided by the NEG-211 particles in addition to the δTc-pinning caused by fluctuation in the transition temperature, Tc, like in ordinary NdBa2Cu3Oy superconductors.

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KW - (Nd,Eu,Gd)BaCuO

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KW - Melt processing

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