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The fabrication of Hg1223 filament was studied through solution spinning method by partial-substituting Sr for the Ba site and Re addition. The precursor (Ba0.8Sr0.2)2Ca2Cu3Re1Oxfilament with diameter of 250 µ m was reacted in a controlled Hg atmosphere. The filament was nearly single phase of Hg1Ba2Ca2Cu3Ox(Hg1223) with Tcof 127 K. The maximum transport critical current density (Jc) of the filament at 77 K and 0 T was attained to 1000 A/cm2. The plane-like grains were packed densely in the filament. The effect of oxygen annealing of the filaments was minor.

The oxygen controlled melt growth process for the filamentary Nd123 superconductor produced by solution spinning to obtain a high Jcwas examined. The filaments have been prepared by dry spinning through a homogeneous aqueous solution containing mixed acetates of Nd, Ba and Cu, poly(vinyl alcohol) and organic acids. By controlling the starting compositions and the melt growth process, a high Tcof 94.5 K and a high Jcof more than 1.3x104A/cm2at 77 K and 0 T were achieved for the filamentary Nd1.18Ba2.12Cu3.09Oxsuperconductor with a diameter of 60 µm. The grains in the sample are not always aligned along the fiber length.

A superconducting F-doped HgxBa2Ca2Cu3Re0.2Oyfilament was produced by a two-step method. The precursor Ba2Ca2Cu3Re0.2Oxfilament was fabricated using a solution spinning method and reacted in an evacuated fused quartz tube with a pellet of Hg1Ba1.8Ca2Cu3Re0.2(BaF2)0.2Ox. The influence of fluorine on the transport Jcof the F-doped Hg1223 filament at 77 K was examined in magnetic fields of up to 10 T. F-doping resulted in a formation of dense liquidus texture and marked improvement in the field dependence of Jcfor the filament. A Jcof more than 102A/cm2was maintained at 77 K in a field of 10 T.

Preparation of an infinite layer of Ca1-xSrxCuO2filaments by solution spinning under ambient pressure was studied. The filament was prepared by dry spinning with a starting homogeneous aqueous solution containing acetates of Ca, Sr and Cu, polyvinyl alcohol and organic acids. Although a single phase of the infinite layer appeared only for the filament with x=0.14, the compositional range for the mixed phase of the infinite layer was expanded to 0.05?x?0.3. Solution spinning lowered the synthetic temperature of the infinite layer by 100°C.

A partial-melt growth process is used to enhance the Jcof solution-spun Y1Ba2Cu3Oxfilaments. The filaments have been prepared by dry spinning through a homogeneous aqueous solution containing mixed acetates of Y, Ba and Cu, polyvinyl alcohol, and organic acids. By controlling the melt growth process of the filaments, dense and highly oriented textures are produced, and a transport critical current density of more than 1×104A/cm2at 77 K and 0 T is achieved for the filaments, each with a diameter of 60 µm.