Submicron size Gd2BaCuO5 particles as source for large critical current densities in (Nd0.33Eu0.33Gd0.33)Ba2Cu3Oy

The effect of (Ndo(0.33)EU(0.33)Gd(0.33))(2) BaCUO5 (NEG-211); and Gd2BaCuO 5 (Gd-211) additions on melt-processed (Nd0.33EU0.33Gd0.33)Ba2CU3Oy (NEG-12 3) composites are investigated using a combination of transmission electron microscopy (TEM) and measurements of critical current densities, Jc. TEM o bservations demonstrate that we could successfully embed submicron-size 211 particles within the NEG-123 matrix. EDX analysis revealed that these subm icron-size particles consist mainly of Gd in the rare earth site. The prese nce of such 211 particles leads to a dramatic increase of J(c) in low field s as well as in the high field region. For NEG-123 with an addition of 40 m ol% of NEG-211 a critical current density of 70 000 A/cm(2) at 77 K, 2.2 T is observed for the field applied parallel to the c axis.