Repository logo
 

The use of buffer pellets to pseudo hot seed (RE)-Ba-Cu-O-(Ag) single grain bulk superconductors


Change log

Authors

Kumar Namburi, D 
Zhao, W 
Durrell, JH 
Dennis, AR 

Abstract

Reliable seeding of the superconducting (RE)Ba₂Cu₃O₇-δ (RE-123) phase is a critical step in the melt growth of large, single grain, (RE)BaCuO [(RE)BCO] bulk superconductors. Recent improvements to the top seeded melt growth (TSMG) processing technique, which is an established method of fabricating bulk (RE)BCO superconductors, based on the use of a buffer layer between the seed and green body preform, has improved significantly the reliability of the single grain growth process. This technique has been used successfully for the primary TSMG and infiltration melt growth (IG) of all compositions within the [(RE)BCO-Ag] family of materials (where RE = Sm, Gd and Y), and in recycling processes. However, the mechanism behind the improved reliability of the melt process is not understood fully and its effect on the superconducting properties of the fully processed single grains is not clear. In this paper, we investigate the effect of the use of a buffer pellet between the seed and green body on the microstructure, critical current, critical temperature and trapped field of the bulk superconductor. We conclude that the introduction of the buffer pellet evolves the melt growth process towards that observed in the technologically challenging hot seeding technique, but has the potential to yield high quality single grain samples but by a commercially viable melt process.

Description

Keywords

buffer, YBCO single grains, hot seeding

Journal Title

Superconductor Science and Technology

Conference Name

Journal ISSN

0953-2048
1361-6668

Volume Title

29

Publisher

IOP Publishing
Sponsorship
Engineering and Physical Sciences Research Council (EP/P00962X/1)
Engineering and Physical Sciences Research Council (EP/K02910X/1)
This work was supported by the Engineering and Physical Sciences Research Council [EPSRC, grant number EP/K02910X/1] and King Abdulaziz City for Science and Technology [KACST].