Influence of Sm and Yb pollution on superconducting properties of YBCO bulk superconductors

Abstract

YBa2Cu3O7-δ (YBCO, Y-123) bulk superconductors with a nominal composition Y1.5Ba2Cu 3Ox and 1 wt% CeO2 addition were prepared by the Top Seeded Melt Growth (TSMG) process. Small single-crystalline pieces, cut from the SmBa2Cu3Oy (Sm-123) bulk, were used for seeding of epitaxial growth. Wavelength-dispersive spectrometry (WDS) confirmed the presence of 0.1 wt% Sm from the seed and 0.25 wt% Yb from the substrate, practically in the whole sample volume. The influence of this Sm and Yb contamination on superconducting properties of grown bulk materials is reported.