10 to 25-fold increase in the transport superconducting critical current density of spark-plasma sintered Bi-2223 superconductors

Author(s)

Govea-Alcaide, E. ^[1] ; Machado, I. F. ^[2] ; Jardim, R. F. ^[3]

Affiliation

^[1] Univ Granma, Fac Ciencias Tecn, Dept Ciencias Basicas, Bayamo - Cuba

^[2] Univ Sao Paulo, Escola Politecn, Dept Engn Mecatron & Sistemas Mecan, BR-05508900 Sao Paulo - Brazil

^[3] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil

• Document type: Journal article
• Source: Journal of Applied Physics; v. 117, n. 4 JAN 28 2015.
• Web of Science Citations: 6

Abstract

Pre-reacted powders of (Bi-Pb)(2)Sr2Ca2Cu3O10+delta (Bi-2223) were consolidated by using the spark plasma sintering (SPS) technique under vacuum and at two different temperatures T-D: 750 and 830 degrees C. The results indicate the occurrence of grains with core-shell morphology, where the shell is oxygen deficient. A post-annealing heat treatment (PAHT), performed in air, at 750 degrees C, and for a brief time interval, is responsible for a 10 to 25-fold increase in the transport superconducting current density at 77 K. The role of the oxygen-deficient shell, before and after the PAHT, was investigated by means of magnetic and transport measurements. We argue that the PAHT is two folds: (i) it is responsible for the decrease of the width of the oxygen-deficient shell, then increasing the oxygen content along the grain boundaries; (ii) it promotes the formation of conduction current paths along the grain boundaries of the SPS material. (C) 2015 AIP Publishing LLC. (AU)

• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC