Jc-B performance of an OCMG processed (Sm0.33Eu0.33Gd0.33)Ba2Cu3Oy with sub-micron Gd2BaCuO5 second phase

Microstructure and critical current density of the melt-textured (Sm0.33EU0.33Gd0.33)Ba2Cu3Oy (SEG-123) superconductors with varying contents of Gd2BaCuO5 (Gd-211) were studied by means of scanning electron microscopy, transmission electron microscopy (TEM), and magnetic measurements with SQUID. The TEM study showed sub-micron secondary phase particles regularly distributed in the SEG-123 matrix. The homogeneous distribution of Gd-211 resulted in a dramatically improved remanent critical current density, even in the samples with only 10 mol% Gd-211. The second peak height did not appreciably change with varying content of Gd-211 up to 30 mol%. Critical current density as high as 83 kA/cm(2) was achieved at 77 K and magnetic field of 2.2 T along c-axis. (C) 2002 Elsevier Science B.V. All rights reserved.