Growth of single crystals of the high-temperature superconductor YBa 2Cu 3O 7-x

We report on the growth of single crystals of the new high temperature superconductor YBa ₂Cu ₃O _7-x ("YBCO"), obtained by a flux method. We used as a solvent the eutectic of two of the constituent oxides, namely a mixture of BaO 28%-CuO 72%. Two crystal species are found to result, one consisting of nearly equidimensional parallelepiped crystals, having linear size up to 2 mm, and another consisting of thin platelets up to 4 mm edge and 0.1 mm thick. By X-ray diffraction, the latter crystals have been oriented and unambiguously identified as YBa ₂Cu ₃O _7-x.