Fluctuation induced magneto-conductivity studies in YBa2Cu3O7-δ + xBaZrO3 composite high-Tc superconductors

Fluctuations on the electrical conductivity of polycrystalline YBa2Cu3O7-delta + xBaZrO(3) (x = 1 0, 2 5, 5 0 and 10 0 wt %) superconductors were investigated from the resistivity vs temperature data for zero field and 8 T (Testa) external magnetic fields Attempts have been made to identify the optimum inclusion of BaZrO3 (BZO) in YBa2Cu3O7-delta (YBCO) superconductors The phase formation, texture and grain alignments were analyzed by XRD and SEM techniques Then the effects of superconducting fluctuations on the electrical conductivity of granular composite superconductors were studied for zero field and 8 T external magnetic fields Though inclusions of BZO sub-micron particles are not expected to influence superconducting order-parameter fluctuation (SCOPF) much, the transition from 2D to 3D of the order parameter in the mean-field region depends on the BZO content in the composites It has been observed that BZO residing at the gram boundary of YBCO matrix influences the tailing region without having significant change in the mean-field critical temperature. In the present work, attention has been focused mostly in the experimental domain relatively above the T-c. It reveals that, 1 wt % composite exhibits a better superconducting property m comparison with pure YBCO (C) 2010 Elsevier B.V. All rights reserved