ABSTRACT
In this chapter, the authors report on the preparation of Lead-stabilized Thallium–Barium–Calcium–Copper Oxide–Superconductors with a single Thallium–oxygen layer structure and of silver-sheathed tape using the oxide powder. The superconductors of Thallium-based systems have an excellent potential for practical applications based on their high critical temperature. For practical use in the fields of power transmission cables, high field magnets, and so on, a critical current density of above 10A/cm is required. Specimens of the tapes were finally heat treated at around 1070 K. The electrical resistivity of the bulk samples was measured by the standard four-probe method and dc magnetic susceptibility by a superconducting quantum interference device magnetometer. Measurement of the transport critical current was carried out between the external magnetic field range of zero to 2.5 T. The direction of the magnetic field applied perpendicularly to the transport current were both parallel and normal to the wide plane of the tapes.
