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

摘要

Recently, we succeeded in fabricating single crystals of PrBa2Cu3O7-delta by a modified top seeded crystal pulling method called the SRL-CP (Solute Rich Liquid-Crystal Pulling) method. Y2O3 and MgO polycrystalline crucibles and a MgO single crystal crucible were used to grow the single crystals. The crystal growth temperature was set in the range of 968 degrees C to 972 degrees C. The grown crystals were identified as PrBa2Cu3O7-delta by X-ray diffraction. In the case of using Y2O3 crucibles 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. According to the crystal growth model of the SRL-CP method [1-5], a maximum growth rate of 1.7 X 10(-5) cm/s was calculated with the aid of the phase diagram studies we reported earlier [6]. This value is reasonably in agreement with the experimental results. [References: 25]