Superconducting Thin Films, Composites and Junctions
Abstract
The important issue of how the superconducting transition temperature T(c) in disordered systems changes near the M-I transition where strong localization (k(F)1 approx. 1) as expected has been studied in the Mo-Ge system. In the high Mo concentration, which is in the weakly localized regime, T(c) decreases linearly with decreasing Mo concentration from 7.5 K (78 at.% Mo) at a rate of approx. 0.18 K/at.% Mo. In this region the ratio of electron-phonon coupling constant gamma to the bare density of states N(b)(O) is constant, which is consistent with the Varma-Dynes tight-binding model. An extrapolation of the linear behavior of T(c) in this regime yields the disappearance of T(c) near 35 at.% Mo. However, measurements show that T(c) exists down to 13.5 at.% Mo. A non-superconducting metallic phase is found to exist between 13.5 at 10.4 at.% Mo at which concentration the insulated phase occurs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1985
- Accession Number
- ADA216688
Entities
People
- Theodore H. Geballe
Organizations
- Stanford University