BULK SUPERCONDUCTIVITY IN SINGLE-CRYSTALS OF PRBA2CU3OX

We report the observation of bulk superconductivity in PrBa2Cu3Ox sing le crystals for the first time. These samples were grown by the travel ling-solvent floating-zone (TSFZ) method in oxygen-reduced atmosphere. The as-grown crystal has a longer c-axis lattice constant an than any values previously reported for oxygen-reduced PrBa2Cu3Ox. After oxyge n annealing, resistivity becomes zero below T = 80 K, and zero-field-c ooled magnetization shows diamagnetism with full volume fraction. X-ra y energy dispersion spectrum and X-ray diffraction analyses show that this superconducting phase is orthorhombic PrBa2Cu3Ox.