Abstract: A method for preparing a BSCCO-2223 oxide superconducting article includes annealing an oxide superconductor article comprised of BSCCO-2223 oxide superconductor at a temperature selected from the range of about 500.degree. C..ltoreq.T.ltoreq.787.degree. C. and an annealing atmosphere having an oxygen pressure selected from within the region having a lower bound defined by the equation, P.sub.O2 (lower).gtoreq.3.5.times.10.sup.10 exp(-32,000/T+273) and an upper bound defined by the equation, P.sub.O2 (upper).ltoreq.1.1.times.10.sup.12 exp(-32,000/T+273). The article is annealed for a time sufficient to provide at least a 10% increase in critical current density as compared to the critical current density of the pre-anneal oxide superconductor article. An oxide superconductor having the formula Bi.sub.2-y Pb.sub.y Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10+x, where 0.ltoreq.x.ltoreq.1.5 and where 0.ltoreq.y.ltoreq.0.

Abstract: A method for preparing an oxide superconductor article includes exposing the article after deformation of the article to a final heat treatment having the steps of (a) heating the article at a temperature sufficient to partially melt the article, such that a liquid phase co-exists with the desired oxide superconductor phase; and (b) cooling to and holding the article at a temperature sufficient to transform the liquid phase into the desired oxide superconductor, where no deformation occurs after the final heat treatment. The liquid phase of step (a) wets surfaces of a defect contained within the mixed phase, whereby upon transformation of the liquid in step (b) to the desired oxide superconductor, the defect is healed.

Abstract: A process for manufacturing superconducting magnetic coils from strain-tolerant, superconducting multi-filament composite conductors is described. The method involves winding the precursor to a multi-filament composite conductor and an insulating material or its precursor around a mandrel in order to form a coil, and then exposing the coil to high temperatures and an oxidizing environment. The insulating material or its precursor is chosen to permit exposure of the superconductor precursor filaments to the oxidizing environment, and to encase the matrix-forming material enclosing the filaments, which is reversibly weakened during processing.

Abstract: In one aspect, the present invention is a precursor powder to an oxide superconductor, namely a coated particle comprising a metal oxide particle core (including a mixed metal oxide, e.g., BSCCO-2212 or YBCO-123) on which is deposited a secondary metal oxide coating (e.g., M.sub.n CuO.sub.x or CuO). The metal oxide particle and secondary metal oxide coating together comprise metallic elements having a stoichiometry appropriate for the formation of a desired oxide superconductor. The metal oxide reacts with the secondary metal oxide under suitable conditions (e.g., heating) to form the desired oxide superconductor (e.g., BSCCO-2223 or YBCO-124). In another aspect, the invention is a method for preparing such a coated particle, comprising: preparing a precursor solution comprising a metal .mu.