Influence of combined Pt and CeO2 additions on microstructure and magneticproperties in (Nd, Eu, Gd)-Ba-Cu-O

We studied the effect of the combined addition of Pt and CeO2 on the disper sion of secondary phase Gd2BaCuO5 (Gd-211) particles in melt-processed (Nd0 .33Eu0.33Gd0.33)Ba2Cu3Oy (NEG-123) by varying the CeO2 content from 0 to 3% . Scanning electron microscopy revealed that submicrometre-sized Gd-211 par ticles were distributed uniformly throughout the NEG-123 matrix for additio ns of up to 2 mol% CeO2. The critical current density (J(c)) increased with increasing CeO2 content, particularly at low magnetic fields. The zero-fie ld J(c) value reached its maximum of 100 kA cm(-2) at 77 K for 1 mol% CeO2. An improvement in low-field J(c) was attributed to the refinement of Gd-21 1 particles.