Improvement of Critical Current Density in YBa₂Cu₃O_6+x Superconductor by Sn Addition

Abstract

When SnO 2 was added to Y-123 (YBa 2 Cu 3 O 6+ x ) powder and sintered at 1223 K for 86.4 ks, the densification was enhanced remarkably, and the density reached 99% of the theoretical value for the 2-mol%-SnO 2 -added specimen, while the average grain size became smaller with Sn addition. Fine spherical BaSnO 3 precipitates were observed to be distributed in the grains and at grain boundaries. The AC magnetization measurements indicated that Sn addition causes intragrain J c m to increase at 77 K in the magnetic field between 0.02 and 0.12 T. The J c m exceeded 10 6 A/cm 2 at 0.04 T for the 3-mol%-SnO 2 -added specimen.