Abstract
We report the results of a calculation of the electron-phonon interaction in Y based on the nonorthogonal tight-binding approach to lattice dynamics. A self-consistent local-density electronic-structure calculation was combined with a shell-model description of the phonon spectrum. The resulting interaction matrix was used to calculate the superconducting transition temperature from a solution of the Eliashberg equations in which the full dependence was retained. The transition temperature was found to be about 90 K, quite close to experiment. The oxygen isotope effect was investigated. We also calculated the -dependent gap function at . The gap shows significant variation between different sheets of the Fermi surface as well as dependence on on the individual sheets, but is nodeless. The quantity varies from 6.0 to 2.5 on the Fermi surface.
- Received 22 February 1994
DOI:https://doi.org/10.1103/PhysRevB.50.9511
©1994 American Physical Society