Abstract: A multifilamentary superconducting composite article includes a plurality of oxide superconducting filaments in a ductile metal matrix arranged about a central core, and a region of high resistivity embedded within and adherent to the metal matrix and substantially surrounding each oxide superconducting filament. The high resistivity region is perforated and the perforation is occupied by a material having a bulk material resistivity greater than 0.4 &mgr;-cm. The article demonstrates a filament to filament resistance greater than 1×10−6 ohm-cm at T>Tc, where resistance is the four-point transport resistance between filaments multiplied by the measured sample length The ac power loss in a field perpendicular to the strand surface or in any other orientation is less than 2.5 mW/A-m at greater than 10 mT (RMS ac field, 30-300 Hz), as measured by magnetic methods without transport current. Methods of manufacture are provided.

Abstract: A multifilamentary superconducting composite article produces from a multifilament assembly which includes a plurality of oxide superconducting filaments in a ductile metal matrix arranged about a central core, the filaments generally having a trapezoidal cross-section. Methods of manufacture are provided.

Abstract: A composite for preparation of an oxide superconductor includes a primary alloy phase of constituent elements of a desired oxide superconductor; and a secondary phase comprising copper, the secondary phase supported by the primary alloy phase. The composite may additionally include a matrix material for supporting the primary alloy phase and second phase disposed therein. The composite is oxidized to form an oxide superconductor composite.

Abstract: A composite for preparation of an oxide superconductor includes a primary alloy phase of constituent elements of a desired oxide superconductor; and a secondary phase comprising copper, the secondary phase supported by the primary alloy phase. The composite may additionally include a matrix material for supporting the primary alloy phase and second phase disposed therein. The composite is oxidized to form an oxide superconductor composite.