POSSIBLE EXPLANATION FOR THE SHAPE OF I-V CU SUPERCONDUCTORS AND A MORE MEANINGFUL DEFI

I have applied a flux creep model to calculate the shape of the I-V characteristic of a superconductor. The functional form mimics an empirical equation , V-I", frequently used to fit data and thus offers a physical justification for its application. The magnetic field dependence of the exponent n is also predicted and compared with experiments. The fits so obtained are encouraging, but call for some experiments specifically designed to test all of the ramifications of the proposed model. I. INTRODUCTION The transport critical current, IC, is one of the most important parameters of a superconducting material. The I, value for a sample is extracted from its measured current- voltage (I-V) curve by constructing a tangent to the steepest part of the curve and extrapolating to 1=0 ( 11. Further analysis