Preparation of doped precursor powders for the fabrication of large grain high temperature superconductors

Abstract

Abstruct-Large single grain RE-Ba-Cu-0 (RE=Y, Nd) high temperature superconductors have been fabricated using a top-seeded melt growth process. These grains have been prepared using powder produced by two solution-based techniques; spray-drying and evaporative decomposition of solution (EDS). The use of these solution-based methods enables the effective addition of small amounts of dopant (such as Pt and Au) to the precursor powder. The dopant refines the size and distribution of non-superconducting phases in the RE-Ba-Cu-0 matrix, which is considered essential for obtaining a high critical current density,

Enhancement ofJcunder magnetic field by Zn doping in melt-textured Y Ba Cu O superconductors

“…Given that the critical current density of bulk (RE)BCO is very dependent on the presence of flux pinning centres, microstructural control is a key factor in the practical application of these materials. Research over the past decade has focused on engineering the (RE)BCO microstructure to increase the number and strength of pinning centres, such as enriching the starting composition with (RE)-211 phase material to form additional pinning centres [3] (e.g., Y-211 or Sm-211 phase in YBa 2 Cu 3 O 7−δ ), addition of Pt to refine the size of these inclusions [4,5], addition of CeO 2 and SnO 2 [6], Au [7] or Ag [1], and, finally, chemical substitutions in the Y-123 matrix, such as the substitution of Y 3+ by Ca 2+ [8] or Cu 2+ by Zn 2+ in Y-123 [9][10][11][12][13][14].…”