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dc.contributor.advisorWilliams, Wyn
dc.contributor.advisorWhaler, Kathy
dc.contributor.authorBarron, Louise Lillias Margaret
dc.date.accessioned2011-08-01T10:23:02Z
dc.date.available2011-08-01T10:23:02Z
dc.date.issued28/06/2011
dc.identifier.urihttp://hdl.handle.net/1842/5023
dc.descriptionNE/D0020366/1
dc.description.abstractMagnetic minerals are abundant within our Earth's crust and can retain, through one of a number of processes, a remanent magnetisation induced by the Earth's magnetic field. Analyses of palaeomagnetic samples have been used for the past fifty years to improve our understanding of many of the Earth's major processes. Recent studies utilising newly developed imaging techniques, namely holographic transmission electron microscopy, have for the first time allowed direct observations of the magnetic structure in palaeomagnetic samples on a nanoscale. It is commonly observed that igneous rocks contain closely packed magnetic lamellae with a non-magnetic matrix, a result of the chemical process of exsolution. However, the results of current micromagnetic models, generated to predict the magnetic structure within such samples, are not in agreement with these direct observations. The results do, however, show strong similarities to the direct observations. The discrepancies between the direct observations and micromagnetic models indicate a lack of understanding of the magnetic interactions within such samples. To examine this two distinct hypotheses have been tested. Firstly, the geometry of the system has been altered to examine the effect of this on the magnetic structure of the grains. Secondly, a multiphase model has been produced. This multiphase model allows the simulation of more complicated systems that include more than one magnetic material in direct contact. This multiphase model has allowed us to examine the effect of varying the exchange in these multiphase structures and its effect on the modelled magnetic structure. Further, this multiphase model has allowed us to examine theoretical systems involving combinations of magnetic materials commonly found in palaeomagnetic samples.en
dc.contributor.sponsorNatural Environment Research Council (NERC)en
dc.language.isoenen
dc.publisherThe University of Edinburghen
dc.relation.haspartThe University of Edinburgh. College of Science and Engineeringen
dc.subjectmicromagnetic modellingen
dc.subjectpalaeomagnetismen
dc.subjectrock magnetismen
dc.titleEffect of exchange and magnetostatic interactions on grain boundariesen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD Doctor of Philosophyen


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