Specific Heat of a Spherical Type-II Superconductor

Abstract

Specific-heat measurements on a spherical 7.05 wt% Pb-In alloy [type-II superconductor with $\ensuremath{\kappa}({T}_{c})=0.72$] are discussed, with special emphasis on the difference in the effect of irreversibility on the determination of Maki's parameters ${\ensuremath{\kappa}}_{1}$ and ${\ensuremath{\kappa}}_{2}$ in calorimetric and magnetization measurements. Evidence is presented to show that ${\ensuremath{\kappa}}_{1}$ can be extracted reliably from specific-heat measurements even in the presence of severe irreversibility. $\frac{{\ensuremath{\kappa}}_{1}(T)}{{\ensuremath{\kappa}}_{1}({T}_{c})}$ showed a much stronger temperature dependence than that predicted by current theories for the case of noninfinite mean free path of the electrons.