Preparation and Characterization of Ba-Y-Cu-O Single Crystals

Abstract
Single crystals of Ba2YCu3O7-y were prepared from molten Ba-Y-Cu-O. The shape of the crystals was thin rectangular slab and the size of the largest crystal was 1.5×1.5×0.04 mm3. The crystals were characterized by resistivity measurement, Meissner effect study and structure analysis. Superconductivity was found with transition temperature of about 90 K by resistivity measurement. The resistivity parallel to the c-axis is 30-90 times larger than in-plane resistivity just above T c. The Meissner effect was also observed in the same sample. The unit cell was orthorhombic with space group Pmmm and the lattice parameters a = 3.857(1), b = 3.865(1) and c = 11.723(4) Å.