University of Illinois - Urbana-Champaign
Upper critical magnetic field of superconducting films with magnetic impurities
Abstract
dc:descriptionWe have measured the upper critical magnetic field, H(T), of c2 In-Mn and Pb-Mn alloy films. Hc2 was determined from the resistance of the films. The results were compared with the theory of Fulde and MakL This theory assumes that the electron-phonon coupling is weak, and that the interaction between the impurity spins and the conduction electron spins is weak. The theory predicts that the pair-breaking effect of the magnetic impurities is temperature-independent, and that the pair-breaking effects of the magnetic impurities and the applied magnetic field are additive. Furthermore, it predicts explicitly the temperature dependence of H' c2 The temperature dependence of Hc2 for the In-Mn alloy films is well described by the Fulde-Maki theory, despite. the moderately strong electron-phonon coupling and the strong interaction between the impurity spins and the conduction electron spins. The temperature dependence of Hc2 for the Pb-Mn alloy films is not well described by the Fulde-Maki theory, probably due to the strong electron-phonon coupling in Ph. However, even without a quantitatively correct theory, one can conclude from the Pb-Mn data that the pair-breaking effect of the magnetic impurities is temperature independent, and that the pair-breaking effects of the magnetic impurities and the applied magnetic field are additive. For Home of the Pb-Mn alloy films, there was a region of positive curvature in H(T) near the zero-field transition temperature. This c2 positive curvature is not understood.
Degree
thesis:*- Name thesis:degree_name
- Ph.D.
- Level thesis:degree_level
- Dissertation
- Discipline thesis:degree_discipline
- Physics
- Year dc:date
- 2011
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Lemberger, Thomas Richard
- Contributors dc:contributor
-
- Ginsberg, D.M.
Subjects
dc:subject × 5Rights
dc:rights- Statement dc:rights
-
- 1978 Thomas Richard Lemberger
- Language dc:language
- en
Identifiers
dc:identifier.*- Identifier
- 356062
- OAI identifier oai:identifier
- oai:www.ideals.illinois.edu:2142/25602