Specific Heat of a Spherical Type-II Superconductor

Specific-heat measurements on a spherical 7.05 wt% Pb-In alloy [type-II superconductor with $\kappa \left(T_c\right)=0.72\mathrm{}$] are discussed, with special emphasis on the difference in the effect of irreversibility on the determination of Maki's parameters ${\kappa }_1$ and ${\kappa }_2$ in calorimetric and magnetization measurements. Evidence is presented to show that ${\kappa }_1$ can be extracted reliably from specific-heat measurements even in the presence of severe irreversibility. $\frac{{\kappa }_1\mathrm{}\left(T\right)\mathrm{}}{{\kappa }_1\left(T_c\right)}$ showed a much stronger temperature dependence than that predicted by current theories for the case of noninfinite mean free path of the electrons.