Phase diagrams in the solid solution Nd-Ba-Cu-O system and NdBa2Cu3O7-δ single crystals growth by the traveling-solvent floating-zone method

We have investigated the pseudo-binary phase diagrams between NdBa2CU3O7-delta (Nd123) and several Ba-Cu-O compositions in air and reduced oxygen atmosphere by DTA, quenching, and X-ray powder diffraction measurements. We found that in air the wider liquidus line exists in the 60-90% concentration of (1/13) Ba3Cu10O13 [40-10% (1/6) Nd123] at 940-1090 degrees C. Under 0.1% O-2 in Ar, the liquidus line on the same pseudo-binary line shifts to the 65-92.5% concentration of (1/13) Ba3Cu10O13 [35-7.5% (1/6) Nd123] at 850-1000 degrees C. Furthermore, we tried to grow single crystals of Nd123 based on these phase diagrams by traveling-solvent floating-zone method under 0.1% O-2 in Ar. We could get a single crystal rod having the composition of Nd1.02Ba1.98CU3O7-delta and the T-c similar to 93 K in all through the length of the crystal rod.