The Resistance of a Superconducting BSCCO-2223 Ag-Sheathed Tape as a Function of Temperature, Current, and Magnetic Field

The electrical transport of a superconducting BSCCO-2223 Ag-sheathed tape is studied as a function of temperature T, current I, and magnetic field H. In a range of current and field, covering two orders of magnitude, the resistance R(T) is described by R = Ro exp{−b[(Tm−T)/(T −To)]0.5}, where To and Tm are the limits of the non-ohmic and field dependent behavior. The threshold To is a decreasing function of I and H, whereas Tm depends only on H. The isothermal R(I) and the R(H) trends confirm the previous function, suggesting that, within the examined ranges, the dissipation may be attributed to a process in which the temperature has a prevalent role, whereas I and H change the limits of the process. The experimental data are consistent with a process in which the dynamics of thermally generated vortices is current and field controlled.