Self-seeded melt growth of Au-doped Nd-Ba-Cu-O

Nd-Ba-Cu-O (NdBCO) precursor powder composed primarily of NdBa2Cu3O7-delta (Nd-123) and 15 mol% Nd4Ba2Cu2O10 (Nd-422) containing 0.1 wt% Au has been p repared by spray drying and subsequent calcination for the fabrication of b ulk melt-processed ceramics. The addition of Au results in the lowering of key process parameters, such as the peritectic melting point and solidifica tion temperatures by up to 30 degreesC. Additional doping of Au/NdBCO with 5 wt% Ag2O lowers these values further and has enabled the successful nucle ation and limited growth of single grains under both air and reduced oxygen atmospheres using undoped NdBCO as a seed. The advantage of this self-seed ed melt growth technique is that it avoids the lattice mismatch that result s from the conventional use of a MgO seed.