Some Properties of Superconductors below 1°K. II. Aluminum and Zinc

Abstract

Magnetic measurements of the threshold curves of superconducting aluminum and zinc of very high purity have been carried out down to 0.3\ifmmode^\circ\else\textdegree\fi{}K. Calculations have been made therefrom of the entropy differences between the normal and superconducting states and of the specific heats of the electron assemblies in both the normal and superconducting states. The value of the linear term for the normal electronic specific heat for Al was found to be $2.59\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}T$ cal./mole/degree and for Zn $1.36\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}T$ cal./mole/degree.