Single Crystal Growth and Improvement of the Superconductivity in Nd1-xPrxBa2Cu3Oy System

Superconducting characteristics have been studied from the viewpoint of the annealing condition on single crystals of the Nd1-x PrxBa2Cu3Oy system grown by the travelling solvent floating zone (TSFZ) method. An anneal as the first step in Ar at 850–900°C gives the best superconducting characteristics in contrast to the anneal in O2. It is suggested that the annealing at high temperature in Ar causes the redistribution between the Pr(Nd)/Ba sites and strongly suppresses the occupancy to the Ba site by the Pr(Nd) ions.