GROWTH AND PROPERTIES OF SUPERCONDUCTING YBCO SINGLE-CRYSTALS

Large, high quality YBa2Cu3O7-x (YBCO) single crystals have been grown by a flux method and characterized by low field magnetization, a-b plane resistivity, microwave surface resistance and heat capacity measurements. The crystals obtained are nearly free standing after crystal growth and are easily harvested. They have dimensions of up to 5 mm along the a-(b-) axis and up to 1 mm along the c-axis. After oxidation, the crystals show a superconducting transition at T(c)=93.2 K with transition width, DELTA-T(c), of < 0.25 K as determined by low field magnetization, a-b plane resistivity and heat capacity data. The heat capacity jump DELTA-C(p) of the superconducting transition is 6.9 mJ/ (g K).