Published February 2000 | Version v1
Journal article

Spatial variations in composition in high-critical-current-density Bi-2223 tapes

  • 1. MST-6, Metallurgy Group, Materials Science Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  • 2. American Superconductor Corporation, Westborough, Massachusetts 01581 (United States)

Description

A detailed compositional analysis of high-critical-current-density (Jc) (55 and 65 kA/cm2 at 77 K) (Bi, Pb)2Sr2Ca2Cu3Oy (Bi-2223) tapes was undertaken by energy dispersive spectroscopy in the transmission electron microscope. Structural features were coupled with characteristic compositions of the Bi-2223 phase. The average of all compositional measurements of the Bi-2223 phase was determined to be Bi1.88Pb0.23Sr1.96Ca1.95Cu2.98Oy. However, spatial variations in the Bi-2223 composition and differing phase equilibria were found throughout the filament structure. In particular, a considerable range of Bi-2223 compositions can be found within a single tape, and the lead content of the Bi-2223 phase is significantly depressed in the vicinity of lead-rich phases. The depletion of lead in the Bi-2223 phase around the 3221 phases may be a current-limiting microstructure in these tapes. (c) 2000 Materials Research Society

Additional details

Publishing Information

Journal Title
Journal of Materials Research
Journal Volume
15
Journal Issue
2
Journal Page Range
p. 285-295
ISSN
0884-2914
CODEN
JMREEE