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Bi-Sr-Ca-Cu-O (BiSCCO) was melted and cast into molds in order to render the superconductor into fully dense and useful shapes. Special conditions for casting and subsequent heat treatments were required to ensure structural integrity and a high transition temperature,Tc.The history of the castings during heat treatments was studied by thermal analysis, X-ray diffraction, and microscopy.

Millimeter-sized crystals of ErBa2Cu3O7 were fortuitously grown while sintering a flat disk. It was possible to separate individual crystals from the sintered mass and measure their properties. The resistive transition and onset of magnetic transition of a single crystal was 93 K and the resistive transition width was < 1 K. Flux expulsion was observed and individual crystals could be levitated by a magnetic field. Crystals showed unusual growth features. They were heavily corrugated along the part of the crystal that grew parallel to the top surface of the disk and that coincided with thec axis of the unit cell. Crystals were characterized by X-rays, electron microscopy, and optical microscopy.

The orthorhombic superconducting phase of YBa2Cu3O7 is shown to be differentiable from its tetragonal precursor by optical microscopy. Individual grains 1 µm in diameter or larger are found to either exhibit the color of the compensator in reflected polarized light (tetragonal material) or to change colors from the compensator (orthorhombic material). By using color differences, retained tetragonal material and the orthorhombic nature of untwinned areas of grains are identified. The advantage to producing better superconducting single crystals and sintered polycrystalline materials is discussed.