RESISTIVE TRANSITION OF BI(2223) SILVER CLAMPED THICK-FILM

Detailed measurements of voltage-current (V-I) curves and magnetoresistance (R-H) for Bi(2223) thick film were carried out for various temperatures and magnetic fields. The results indicate that a flux lattice melting transition takes place as the temperature and the field are raised. This transition boundary in the (H,T) phase diagram was found to follow the irreversibility line described by the function of H=H-0(1-T/T(c))3/2 . Above this line, the V-I curves display a flux-flow-like character. Temperature and magnetic field dependencies of flow resistance R(f)-T and R(f)-H show a varied viscosity in different temperature and field ranges. Below this line, V-I curves in the low voltage region present a thermally activated flux creep property. The R-H measurements indicate that the fields at the onset and the midpoint of the magnetoresistive transition also follow a (1-T/T(c))3/2 dependence.