Enhancement of critical current density and irreversibility field by Te or TeO2 addition to MgB2 bulk processed by spark plasma sintering

Te metal or TeO2 were added to MgB2 ((MgB2) + (A)x, x = 0.005, 0.01, 0.03, A = addition). The mixtures were processed by spark plasma sintering. The critical current density, Jc, of the samples containing the Te/TeO2 additions is enhanced at high fields and at temperatures up to 20 K. The curve of Jc(5 K, H) for the sample with optimum xTe = 0.01 shows no accelerated decrease up to 8 T (Jc(5 K, 8 T) = 1.8 × 103 A cm−2). The irreversibility field of the samples containing the Te/TeO2 additions is also enhanced.