Quantum corrections to the conductivity have been studied at low temperatures down to 0.15K and fields up to 8.8T in two different disordered systems, namely amorphous Ca-Al alloys doped with Ag and Au and icosahedral Al-Cu-Fe alloys. In the former the influence of spin-orbit scattering on the enhanced electron-electron contribution to the resistivity has been, for the first time, clearly displayed. As the spin-orbit scattering rate increases, this contribution decreases rapidly to finally vanish at extremely high spin-orbit scattering rates. Furthermore the analysis shows that the current weak localization theory gives an accurate description of the experiments irrespective of the level of spin-orbit scattering. / In icosahedral Al-Cu-Fe alloys, detailed study of the low temperature resistivity shows that the magnetoresistance and the temperature dependence of the resistivity data are consistent with the predictions of quantum corrections to the conductivity theories. The success of these theories in this alloy system is attributed to intense electron scattering due to disorder. The spin-orbit scattering and the electron wave-function dephasing rates are extracted from fitting the magnetoresistance. The dephasing rate is found to vary as AT$ sp{p}$ with $p sim1.5$; a characteristic of electron-electron scattering in the strong disorder limit. An antilocalization effect has also been directly observed in the temperature dependence of the resistivity in one of the samples.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.39541 |
| Date | January 1992 |
| Creators | Sahnoune, Abdelhadi |
| Contributors | Strom-Olsen, John O. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001324575, proquestno: NN87676, Theses scanned by UMI/ProQuest. |
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