The superconducting gap in a CeRu2 single crystal is investigated by point contacts. BCS-like behavior of the gap Δ in the temperature range below Tc* (Tc *<Tc, where Tc is the critical temperature) is established, indicating the presence of a gapless superconductivity region (between Tc* and T c). The pair-breaking effect of paramagnetic impurities, supposedly Ce ions, is taken into consideration using the Scalski-Betbeder-Matibet-Weiss approach based on Abrikosov-Gorkov theory. It allows us to recalculate the superconducting order parameter Δα (in the presence of paramagnetic impurities) and the gap Δp (in the pure case) for the single crystal and for the previously studied polycrystalline CeRu 2. The value 2Δp(0)≈2 meV, with 2Δp(0)/kBTc≈3.75, is found in both cases, indicating that CeRu2 is a "moderate" strong-coupling superconductor.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)