Tunneling characteristics of junctions of the form AlOx-Pd-Pb are reported. From the thickness dependences of Tc and the induced gaps we find that the total BCS interaction (NV) in Pd is 0±0.05. We find a Fermi velocity of ∼ 0.2×108 cm/sec indicating that the narrow d-band electrons dominate our measurements. Pd phonon structure is not resolved, setting an upper limit of λ0.2 for the effective electron-phonon interaction. These results indicate that paramagnon effects are substantially less important for superconductivity than was previously envisioned.
ASJC Scopus subject areas
- Physics and Astronomy(all)