FABRICATION AND GROWTH-RATE ESTIMATION OF PRBA2CU3O7-DELTA SINGLE-CRYSTAL BY THE MODIFIED TOP SEEDED CRYSTAL PULLING METHOD

Recently, we succeeded in fabricating single crystals of PrBa2Cu3O7-de lta by a modified top seeded crystal pulling method called the SRL-CP (Solute Rich Liquid-Crystal Pulling) method. Y2O3 and MgO polycrystall ine crucibles and a MgO single crystal crucible were used to grow the single crystals. The crystal growth temperature was set in the range o f 968 degrees C to 972 degrees C. The grown crystals were identified a s PrBa2Cu3O7-delta by X-ray diffraction. In the case of using Y2O3 cru cibles the composition of the grown crystals was YxPr1-xBa2Cu3O7-delta (0.48 < x < 0.57) and in the case of using MgO crucibles a relatively small amount of Mg contamination to the grown crystals occurred at a typical concentration of approximately 1 at.% of the sum of cations. A ccording to the crystal growth model of the SRL-CP method [1-5], a max imum growth rate of 1.7 X 10(-5) cm/s was calculated with the aid of t he phase diagram studies we reported earlier [6]. This value is reason ably in agreement with the experimental results.