METHOD OF PREPARING SUPERCONDUCTING CERAMIC POWDERS Bi(Pb)-Sr-Ca-Cu-O

摘要

FIELD: superconducting materials. SUBSTANCE: invention relates to synthesis of high-temperature conductor precursors and can be used in manufacturing superconducting ceramics and products based on it: both voluminous ones and composite long-length conductors with ceramic core (single-core and multicore- type) with metallic shell. Solution is prepared from nitrates of bismuth 0.126-0.251 M, lead 0.028-0.056 M, strontium 0.140-0.279 M, calcium 0.154-0.307 M, and copper 0.209-0.418 M. Solution of precipitating agent is prepared from sodium or potassium oxalate (to 0.188-0.375 M) and corresponding hydroxide (to 0.305-0.610 M). Joined precipitation is accomplished by mixing together nitrate and precipitator solutions within pH range 10.4-12.3 at 90-100 C. Precipitate is filtered off, washed 5-9 times for 3-7 min with 14-20 ml/g of water at 90-100 C, dried, and thermally treated. Resultant powder is distinguished by reduced sodium and potassium contents (to 0.01 wt %), decreased more than by 30% superconductivity transfer range (because of increased composition and structure homogeneity), raised by 4-6 K superconductivity transfer temperature, and extended by 4.5 times joined precipitation pH range. EFFECT: increased more than fivefold productivity and enabled large- scale production. 4 cl