Degree Type

Dissertation

Date of Award

1981

Degree Name

Doctor of Philosophy

Department

Physics and Astronomy

Abstract

Heat capacities have been measured in the presence of magnetic fields for Cu-Nb and Cu-Nb(,3)Sn in situ composites in order to determine the size of the superconducting pair potential which is induced in the normal Cu region as a function of magnetic field. For the Cu-Nb composites the induced pair potential is found to be about 0.35 meV in zero field, in agreement with de Gennes boundary conditions. With the application of a magnetic field, the energy gap declines quickly and above about 17 mT the Cu behaves as a gapless superconductor. A family of life-time broadened density of states which gives the measured C(,es)(Cu) is calculated based on the relation between the entropy S and density of states N((omega)) derived for superconductors doped with paramagnetic impurities. Similar results are found in Cu-Nb(,3)Sn composites.

DOI

https://doi.org/10.31274/rtd-180813-4670

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Shelly Sit-Ling Shum Eucker

Language

en

Proquest ID

AAI8128813

File Format

application/pdf

File Size

94 pages

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