Abstract
Resistivity, susceptibility, and specific heat measurements on the new layered superconductors and have been performed to characterize their superconducting state. Our experiments indicate bulk superconductivity with for and for . An analysis of the specific heat anomalies at in terms of the weak coupling BCS and the two-fluid model, as well as estimates based on McMillan's formula, reveals strong electron-phonon coupling in the present systems, in contrast to the related three-dimensional superconductor with .
- Received 30 October 1995
DOI:https://doi.org/10.1103/PhysRevLett.77.374
©1996 American Physical Society