Superconductivity, Susceptibility, and Specific Heat in the Noble Transition Elements and Alloys. II. Comparison with Theory

Abstract

The results of an experimental study of the superconducting transition temperature $T_c$, the magnetic susceptibility $\chi$, and the electronic specific heat $\gamma T$ in noble transition metals are discussed in terms of the existing theory for the interactions which affect these parameters. Particular attention is paid to the possible presence of virtual ferromagnetic spin fluctuations in these paramagnetic metals, using the recent theory of Berk and Schrieffer. The existing data do not prove that the spin fluctuations are suppressing the superconducting transition temperature; however, this seems to be the most reasonable explanation for the strong correlation between the decreasing $T_c$ and the increasing ratio of $\frac{\chi }{\gamma }$. We present calculated values for the variation of the bare density of states, the phonon interaction, the Coulomb interaction, and the spin susceptibility in these metals.