Proximity electron-tunneling study of superconductivity in transition metals and as induced in a normal metal, Mg
Conventional Nb tunneling junctions have been fabricated by completely oxidizing a 10 to 15 A layer of deposited Al, avoiding thermal oxidation of the Nb. Comparison of the resulting conventional Nb pair potential and Eliashberg spectral function, ..cap alpha../sup 2/F(..omega..), with those of proximity (PETS) analyses shows excellent agreement confirming the appropriateness and accuracy of the PETS analytic procedure. The PET methodology is further adapted to proximity systems employing Mg as the N-layer backed by Nb and Ta foils S. A detailed study of C-MgO/sub x/-MgNb systems for Mg thicknesses ranging from 25 A to 1100 A and C-MgO/sub x/-MgTa systems over a narrower thickness range shows anamalous thickness dependence for the junction conductance resulting from an increased scattering presence over that seen in Al-Nb systems. As a result, the Nb phonon contributions are completely damped for Mg thicknesses greater than 400 A, allowing unimpeded determination of the Mg ..cap alpha../sup 2/F(..omega..). The resulting Eliashberg spectral function reveals the electron-phonon coupling, ..cap alpha../sup 2/(..omega..), to be greatly reduced for transverse phonon frequencies relative to its longitudinal phonon value.
- Research Organization:
- Ames Lab., IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5994469
- Report Number(s):
- IS-T-1073; ON: DE83016412
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
MAGNESIUM
SUPERCONDUCTIVITY
NIOBIUM
SUPERCONDUCTING JUNCTIONS
TUNNEL EFFECT
ELECTRON-PHONON COUPLING
PHONONS
PROXIMITY EFFECT
ALKALINE EARTH METALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
JUNCTIONS
METALS
PHYSICAL PROPERTIES
QUASI PARTICLES
TRANSITION ELEMENTS
420201* - Engineering- Cryogenic Equipment & Devices