An intrinsic dissipative process in planar superconductors at zero applied field

The non-ohmic response of several II type planar superconductors in absence of magnetic field is examined as a function of temperature and current. The scaling of the R(T) data at constant current is obtained by plotting the resistance R vs. Q = [T-To(I)]/[Tm-To(I)], where To(I) and Tm are the temperature limits of the non-ohmic response in the R(T) dependence. Such scaling is obtained in all the considered samples and it seems to be independent on the boundary effects in granular specimens and on the interlayer coupling in multi-planar systems. Because of the variety of the examined samples this behavior appears to be an intrinsic characteristic of planar superconductors. The R(Q) trend is well approximated by R = Ro exp {-b √[(1/Q)-1]} and an interpretation based on the current assisted depairing of thermally excited vortex-antivortex pairs is proposed