Oxide superconductor precursors

A composite for use in the preparation of an oxide superconductor composite, comprising;

• a primary alloy phase comprising a portion of the constituent metallic elements of an oxide superconductor and a noble metal, said primary alloy phase deficient in copper;
• a secondary metallic phase comprising copper,
• wherein substantially all of the copper of the composite is present in the secondary phase,
• wherein said secondary phase is positioned in intimate contact with the primary alloy phase to permit exchange of elements between the phases, and
• wherein the constituent elements of the primary alloy phase and the copper of the secondary phase are, in combination, present in a substantially stoichiometric amount to form the oxide superconductor;
• and
• a noble metal matrix material, within which the primary alloy phase and the secondary phase are disposed.

A precursor composite for use in the preparation of a copper metal-free oxide superconductor composite, comprising;

• a primary alloy phase comprising a portion of the constituent metallic elements of an oxide superconductor and a noble metal, the noble metal selected from the group consisting of Ag, Au, Pt, Pd and alloys thereof, said primary alloy phase deficient in copper;
• and
• a secondary metallic phase comprising copper,
• wherein substantially all of the copper of the composite is present in the secondary phase,
• wherein said secondary phase is positioned in intimate contact with the primary alloy phase to permit exchange of elements between the phases, and
• wherein copper is present in an amount no greater than 30% stoichiometric excess with respect to the copper stoichiometry of the oxide superconductor and the remaining constituent elements are present in a substantially stoichiometric amount to form the oxide superconductor.

A precursor composite for use in the preparation of a copper metal-free oxide superconductor composite, comprising;

• a primary alloy phase comprising a portion of the constituent metallic elements of an oxide superconductor and a noble metal, the noble metal selected from the group consisting of Ag, Au, Pt, Pd and alloys thereof, said primary alloy phase deficient in copper;
• a secondary metallic phase comprising copper,
• wherein substantially all of the copper of the composite is present in the secondary phase,
• wherein said secondary phase is positioned in intimate contact with the primary alloy phase to permit exchange of elements between the phases, and
• wherein copper is present in an amount no greater than 30% stoichiometric excess with respect to the copper stoichiometry of the oxide superconductor and the remaining constituent elements are present in a substantially stoichiometric amount to form the oxide superconductor;
• and
• a noble metal matrix material, the noble metal selected from the group consisting of Ag, Au, Pt, Pd and allows thereof, within which the primary alloy phase and the secondary phase are disposed.