SUPERCONDUCTIVITY AND CRYSTAL-GROWTH OF YBCO GROWN UNDER 1 ATM OXYGEN-PRESSURE

YBCO (Y123) single crystals were grown under 1 atm oxygen pressure by using the crystal pulling method. After annealing, critical temperatur e T-c was measured to be 92.7 K, which is nearly the same as those of the crystals grown in low oxygen partial pressure and air atmosphere. This indicates that the substitution of Y for Ba and T-c are not sensi tive to the oxygen partial pressure of the growth atmosphere. Moreover , it was clarified that high oxygen partial pressure has a profound ef fect on growth rate, which is about 1.5-2.5 times larger under 1 arm o xygen pressure than under air atmosphere.