Superconducting oxide FCC oxide composite compositions and method of making such compositions
AssigneeW. R. Grace & Co.-Conn.
InventorNicholas D. Spencer
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Abstract
Two or more superconductors are reacted together to form a non-superconducting phase encapsulating a residual superconducting phase. For example YBa.sub.2 Cu.sub.3 oxide is reacted with Bi.sub.2 Sr.sub.2 CaCu.sub.2 oxide to form a superconducting product containing a novel non-superconducting oxide of Y, Bi, and Ba. A superconducting YBa.sub.2 Cu.sub.3 oxide remains as an interconnected phase throughout the product. The new non-superconducting phase largely encapsulates and insulates the superconducting phase.
Claims7
Oxide of Y, Bi, and Ba, in a face-centered cubic phase with a=8.55 Angstroms and having a semi-conductor to metal transition at about 120.degree. K.
Process comprising reacting together at least two superconducting to form a superconducting product containing a non-superconducting component, wherein at least one of the superconductor reactants is an oxide containing L-M-A where:
- L is at least one trivalent metal, including bismuth and the rare earth group including scandium and yttrium;
- M is at least one bivalent Metal, including barium, beryllium, magnesium, calcium, and strontium;
- and
- A is at least one metal of multiple valency including niobium, copper, silver and gold.
Process of preparing superconducting oxide of Bi, Sr, Ca, Y, Ba, and Cu comprising:
- (A) reacting aqueous solution of nitrates of Bi, Sr, Ca, Y, Ba, and Cu with a stoichiometric equivalent of a solution of quaternary ammonium, carbonate so as to form coprecipitates of the carbonates of Bi, Sr, Ca, Y, Ba, and Cu and to provide excess YBa.sub.2 Cu.sub.3 ;
- (B) recovering and drying the carbonates;
- and
- (C) calcining the dried carbonates to form a composition containing an oxide of Y, Bi, and Ba in a face-centered cubic phase with a=8.55 Angstroms and having a semi-conductor to metal transition at about 120.degree. K. and also containing a superconducting oxide of YBa.sub.2 Cu.sub.3 as an interconnected phase.
Process comprising reacting superconducting orthorhombic YBa.sub.2 Cu.sub.3 oxide with superconducting Bi.sub.2 Sr.sub.2 CaCu.sub.2 oxide to form a superconducting product consisting essentially of:
- (I) a nonsuperconducting compound containing oxide of Y, Bi, and Ba, with traces of Sr, Ca, and Cu, having a face-centered cubic phase with a=8.55 Angstroms, and a semi-conductor-to-metal transition at about 120.degree. K.;
- and
- (II) a tetragonal superconducting YBa.sub.2 Cu.sub.3 oxide as an interconnected phase throughout the product.
Dependencies are inferred from the claim text.