MgB2 with Addition of Bi2O3 Obtained by Spark Plasma Sintering Technique

Bi2O3 and Bi-metal powders were mixed with MgB2 powder. Starting compositions were (MgB2)(Bi2O3)x, x=0.0025, 0.005, 0.015, and (MgB2)(Bi)y, y=0.01. Mixtures were processed by Spark Plasma Sintering (SPS) technique. As obtained composite samples show high density, above 94 % of the theoretical density. Samples with Bi2O3 for x=0.0025 and 0.005 show higher critical current densities, Jc, at high fields and at 20 K than for the pristine sample. Their irreversibility field, Hirr, is also higher. On the other hand, sample added with Bi-metal has lower Jc and Hirr at any temperature than for the pristine sample.