Flux pinning in melt-processed ternary (Nd-Eu-Gd) and Nd-based superconductors

Author

Pradhan, A.K. ; Muralidhar, M. ; Feng, Y. ; Shibata, S. ; Murakami, M. ; Nakao, K. ; Koshizuka, N.

Author_Institution

Supercond. Res. Lab., ISTEC, Tokyo, Japan

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

3706

Lastpage

3711

Abstract

We report on the flux pinning and optimization of melt-processed ternary (Nd-Eu-Gd)Ba₂Cu_37-x bulk materials using magnetization and magneto-transport (quasi-flux transformer technique) measurements. The highest flux pinning was observed for the optimal annealing condition, where twin planes act as correlated pinning in the presence of the optimal second-phase addition. The addition of Ag decreases the low-field critical current density, whereas high-field behavior does not change drastically. The results were compared with NdBa₂Cu₃O_7-x single crystals that show various vortex states with increasing defect density. The melt-processed samples demonstrate very similar behavior to the single crystal. The interplay between the point defect and the twin planes resulting an entangled vortex liquid-state remains valid for both single crystals and melt-processed samples

Keywords

annealing; barium compounds; critical current density (superconductivity); europium compounds; flux pinning; gadolinium compounds; high-temperature superconductors; magnetisation; magnetoresistance; neodymium compounds; point defects; silver; twin boundaries; Ag; Nd-based superconductors; NdBa₂Cu₃O_7-x single crystals; NdEuGdBa₂Cu₃O₇:Ag; defect density; entangled vortex liquid-state; flux pinning; low-field critical current density; magnetization; magneto-transport; melt-processed Nd-based superconductors; melt-processed samples; melt-processed ternary (Nd-Eu-Gd)Ba₂Cu_37-x bulk materials; optimal annealing condition; point defects; quasi-flux transformer technique; single crystals; twin planes; vortex states; Critical current density; Crystalline materials; Crystals; Flux pinning; Laboratories; Magnetic materials; Superconducting materials; Superconductivity; Telephony; Yttrium barium copper oxide;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919869

Filename

919869