Pinning potential, its relativity and dependence on temperature and magnetic field studied on the basis of theI-Vcharacteristics of multifilamentary superconductors

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Abstract
A series of I - V characteristics of multifilamentary superconductors measured at various temperatures (2.4 - 4.2 K) and magnetic fields (6 - 12 T) was analysed with the help of creep process theory. It was shown that the current-dependent effective pinning potential as well as the temperature- and magnetic field-dependent pinning potential depend on the choice of the reference current - voltage point in some of the currently used models. Due to this fact, the values of as well as derived from I - V data have a meaning related to a reference current - voltage point chosen usually in the practically accessible measurement range. In this paper, we used 1 as the reference voltage. Generalizing some features of creep models we found the way to derive from experimental data without knowing the precise form of the dependence. The influence of technological parameters (filament composition and heat treatment conditions) on this relative pinning potential are discussed. A simple scaling of was found for all the conductors under study. Its form is , where the values of scaling temperatures are very close to the critical temperatures and seems to be a maximum value of the relative pinning potential at a given magnetic field in the whole temperature range.