Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.459732
Title: An investigation of liquid noble metal alloys using nuclear magnetic resonance
Author: Host, Ian Peter
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 1971
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Abstract:
Nuclear magnetic resonance (NMR) Knight shift and spin-lattice relaxation time measurenents of 63CU, 115In and 119Sn in some liquid noble metal-indium alloys and noble metal-tin alloys are presented together with magnetic susceptibility measurements in the liquid noble metal-indium systems and gold-tin system. The problems associated with the preparation of suitable powder samples for NMR studies are discussed together with some original methods of solving them. The measured properties are first examined in the light of the information they yield regarding atomic distributions in liquid alloys. In contrast to some earlier X-ray and neutron diffraction data the NMR results do not indicate that any short range atomic ordering is taking place in any of these systems. Assuming that the alloy systems are random mixtures of the two components, an attempt is then made to reproduce the observed Knight-shift data by using spin susceptibilities deduced from the total susceptibility data together with a calculation of the conduction electron contact density at the nucleus using firstly a partial wave analysis of the electron-scattering and secondly a pseudopotential approach. Both calculations give semi-quantitative agreement with experiment. The relaxation rate data for these systems are then considered. For the noble metal-tin systems the relaxation rate of 119Sn is wholly accounted for by the magnetic contribution predicted from the observed Knight shift through the Korringa relation. However in the noble metal-indium alloys the relaxation rates for 115In, and to a lesser extent 63Cu, can only be wholly described by both magnetic and quadrupolar contributions. The latter can be understood qualitatively in terms of a theory due to Sholl. Finally an NMR investigation of the solvent 133Cs resonance in the liquid cesium-oxygen system is presented, The results strongly favour a model in which the oxygen exists in doubly ionized form in the metal matrix.
Supervisor: Not available Sponsor: Atomic Energy Research Establishment (Harwell, England)
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.459732  DOI: Not available
Keywords: QC Physics
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