Processing of single-phase ceramic 123 YBaCu-oxide superconductor by hot pressing

High-quality, single-phase, polycrystalline samples of high-temperature superconducting 123 YBaCu-oxide have been processed by hot pressing of specially prepared charge material at elevated temperatures. The samples are orthorhombic with unit cell dimensions a = 3.824 (1) /angstrom/, b = 3.888 (1) /angstrom/, and c = 11.679 (2) /angstrom/. They exhibit: (i) densities up to 82% of the theoretical values; (2) a sharp phase transition between the normal and superconducting states at 91.6 K; (3) a reduced dependence on thermal cycling effects and on excitation currents in resistivity measurements; and (4) a reduction in surface deterioration due to water, air, and acid attack. The hot-pressed samples supported current densities at least two orders of magnitude greater than those found in cold-pressed samples measured under similar conditions