Effect of CeO2 addition on microstructure and magnetic properties in (Nd,Eu,Gd)-Ba-Cu-O

Morphology of Gd2BaCuO5 (Gd-211) secondary phase particles in an oxygen-con trolled-melt-growth processed (Nd0.33Eu0.33Gd0.33)Ba2Cu3Oy + 0.5 mol% of Pt (NEG-123) was studied as a function of varying amount (0-3 mol%) of CeO2. Optical and scanning electron microscopy revealed that sub-micron Gd-211 pa rticles were distributed uniformly throughout the NEG-123 matrix for additi ons of up to 2 mol% Of CeO2. With increasing CeO2 content the critical curr ent density, J(c), increased particularly at low magnetic fields. The maxim um value of J(c) was achieved for 1 mol% CeO2 and reached 100 kA cm(-2) at zero field and 77 K. The improved low-field critical current density is att ributed to the refinement of Gd-211 particles. (C) 2001 Elsevier Science B. V. All rights reserved.