Growth of superconducting and non-superconducting whiskers in the Bi-Sr-Ca-Cu-O (BSCCO) system

P. Badica

Institute for Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577 Japan, and National Institute of Materials Physics, Bucharest-Magurele, 077125, POB MG-7, Romania

K. Togano

Institute for Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577 Japan, and National Institute for Materials Science, Tsukuba, 305-0047 Japan

Growth of such non-superconducting whiskers as Sr_2.24Ca_0.4Al₂O_x, (Ca_0.8-0.85Sr_0.15-0.1)₂CuO₃, CuO, and Bi_2.44Sr₂Ca_1.3-2Cu_6.9-9.95Al_0.35-0.46O_x (Cu-rich whiskers) formed during the growth of Bi-2212 superconducting whiskers from powder or glassy substrates, is discussed. These whiskers are likely to grow from the bottom end, and there is a tight relationship with the growth of the Bi-2212 whiskers. A general reaction-path model for the whisker growth in the BSCCO system, independent of the type of the catalytic impurity and substrate, is proposed. When whiskers are grown under magnetic fields, up to 10 T, changes in the whisker size, aspect ratio, and morphology are observed.