In this investigation, an attempt is made to correlate magnetic susceptibility and nuclear magnetic resonance properties in a wide variety of metallic systems. Such an approach is adopted in order to obtain greater insight into the atomic and electronic structure of these systems. The magnetic susceptibility of several pure metals in the solid and liquid phases is presented and it is shown that in the liquid at least these can be understood in terms of free interacting conduction electrons. Thus, in these metals the spin contribution to the susceptibility (related to the Knight shift) can be confidently estimated. The measured values of the Knight shifts in these pure liquid metals are then compared with those calculated from the susceptibility and the conduction electron wave function density at the nucleus, found using a pseudopotential method. It is seen that the temperature variations of the shifts are better explained than their absolute values. In view of the greater success of the prediction of fractional changes the approach is extended to the concentration dependence of the shift upon alloying. Experimental results are presented for the 113 Cd and 119 Sn resonance shifts and the magnetic susceptibility in tin-cadmium alloys (a system chosen for its simplicity). These shifts are compared with values calculated using either the pseudopotential method or the more limited partial wave analysis. Good agreement is found and the method of correlation is extended to less simple systems. It is used with success to separate spin and orbital contributions to the shift and susceptibility in the transition metal oxide, V0 2 , but is of more limited use in heavy metal alloys and in those suspected of liquid atomic ordering or of localised magnetic moment formation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:594989 |
| Date | January 1972 |
| Creators | Ford, Christopher John |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/71386/ |
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