TY - JOUR
T1 - Refinement of secondary phase particles for high critical current densities in (Nd,Eu,Gd)-Ba-Cu-O superconductors
AU - Muralidhar, M.
AU - Koblischka, M. R.
AU - Murakami, M.
N1 - Funding Information:
This work was partially supported by NEDO for the R&D of Indust. Sci. and Tech. Frontier program. MMD is thankful to the Iwate Techno Foundation, Iwate, Japan for providing the financial assistance, and MRK thanks the Japanese Science and Technology Agency (STA) for providing the fellowship.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
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.
KW - (Nd,Eu,Gd)BaCuO
KW - (Nd,Eu,Gd)BaCuO
KW - Critical current density
KW - Flux pinning
KW - Melt processing
KW - Microstructure
KW - Peak effect
KW - Pt addition
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U2 - 10.1016/S0921-4534(99)00017-9
DO - 10.1016/S0921-4534(99)00017-9
M3 - Article
AN - SCOPUS:0033077399
VL - 313
SP - 232
EP - 240
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - 3-4
ER -