The influence of pyrolysis condition on the partial melting of solution-spun Y₁Ba₂Cu₃O _x superconducting filament

Abstract

The precursor filaments with diameters of 300 and 110 μm were spun through a homogeneous aqueous poly(vinyl alcohol) (PVA) solution containing Y, Ba and Cu acetates. The as-drawn filaments were pyrolysed at a slow heating rate of 30 °Ch⁻¹ to remove volatile components and partially melted. The effect of pyrolysis condition on the partial melting of the filament was examined to enhance the reproducibility of the highJ _c. By controlling the solidifying condition for the filament pyrolysed at 500 and 450 °C, a highJ _c of more than 10⁴ A cm⁻² at 77 K and 0 T was attained. A window of heating condition to obtain the highJ _c for the thin filament was narrow as compared with the thick filament. The optimum condition for the filament pyrolysed at 450 °C became wider than that for pyrolysing at 500 °C.