Electronic and superconducting properties of Mo-Ta superlattices

We obtain bcc-bcc Mo-Ta superlattices in the modulation wavelength range 16--450 A. The x-ray analysis shows long structural coherence even in the short-modulation-wavelength limit, and the resistivity data are in the metallic regime. We find the ''universal'' behavior of the T/sub c/ versus rho curve already seen in other metals, compounds, and alloys and, for superlattices in the range 50--250 A, the dV/dI versus V characteristics show a double-peak structure. The temperature behavior of these peaks is fitted by a two-band model and by a proximity-effect theory.