Critical Current Distribution and Flux Creep Properties in Y1Ba2Cu3O7-δ Superconducting Thin Films

Current-voltage (I-V) characteristics of Y1Ba2Cu3O7-δ thin films were studied in a wide range of 10−4 to 102 V/m. Isolation of flux creep and flux flow was discussed with frequency dependence of I-V curve. By use of series domain network model, critical current distribution was estimated from non-linear I-V curves. Furthermore, an expression of flux creep considering the inhomogeneous critical current was derived. Comparing the expression and measurements, we determined pinning potential and the boundary between flux creep and flux flow. It was shown the obtained expression agreed well with the measurement in more than six decades.