EFFECTS OF Gd DOPING IN YBa₂Cu₃O_7-delta ON THE CRITICAL CURRENT DENSITY

Abstract

Gd is successfully embedded into YBa 2 Cu 3 O 7-δ by the solid state reaction. Rietveld refinements show that Gd replaces Cu in the unit cell. By magnetization and resistivity measurements, the effects of Gd -doping in YBCO on the critical current density J c and the critical temperature T c in YBa 2 Cu 3 O 7-δ( YBCO ) have been investigated. J c varies with the applied field and the content of Gd and has a maximum at x = 0.03. The characteristic behavior of J c with varying the Gd content can be explained in terms of the competition between two different effects caused by Gd -doping in YBCO: the inhomogeneity of grains distribution in nano-scale and the variation of superconductivity.

Effect of Mn Addition on In-Field Behavior of IBAD/MOCVD Gd-YBCO Second Generation HTS Tapes

“…Both studies indicated the enhanced pinning to be due to stress fields induced by lattice mismatch. Xu et al have studied the effects of Gd substitution on Cu sites in YBCO on the critical current density for Gd concentrations between 0 and 20% [2]. They reported a 'zigzag' variation of critical current density with increasing Gd concentration, and found an optimum concentration to be 0.03 in where x is in mole concentration from 0 to 0.2.…”