Infiltration growth of Mg-doped Nd–Ba–Cu–O seed crystals for the fabrication of large grain RE–Ba–Cu–O bulk superconductors

Abstract

By employing the infiltration growth (IG) technique, Mg-doped Nd–Ba–Cu–O (NdBCO) seed crystals were successfully prepared through 1 wt% MgO addition both to a Nd4Ba2Cu2O10 (Nd-422) precursor powder and to a liquid source with the composition Nd2O3:CuO:BaCuO2 = 1:6:10. Differential thermal analysis (DTA) results showed that the decomposition temperature of the processed Mg-doped NdBCO crystals increased by about 20 °C compared with the general, Mg-free NdBCO seeds, thus they can be used as generic seed crystals to induce the growth of any RE–Ba–Cu–O (REBCO) single grain. This result is consistent with that observed in melt growth (MG) processed Mg-doped NdBCO crystals. Finally, highly c-axis oriented Gd–Ba–Cu–O (GdBCO) and Y–Ba–Cu–O (YBCO) large grains were successfully grown using the produced seed crystals.