Applications of microRaman spectroscopy to the study of petrological, mineralogical and natural structural materials
thesisposted on 15.12.2014, 10:39 by Matthew J. Bloomfield
MicroRaman spectroscopy represents a powerful tool for the study of crystal structure and identification of materials. Despite being widely used in other areas of scientific research it has yet to become a routine analytical technique within the Earth Sciences.;Case studies are used to describe the application of this technique. Using the different approaches available a variety of materials of a mineralogical and petrographic nature are used to assess the usefulness and applicability of the technique.;Following a brief review of the fundamental theory of Raman scattering, a description of the analytical instruments is given and the format of the thesis explained. An existing database of mineral spectra is assessed, comprehensively edited and suggestions made for improvements. Mineral identification is implemented on several samples to emphasize advantages over other techniques. Investigations of changes in crystal structure are performed on biotite radiohaloes, zircons and quartz on the basis of spectra acquired. Dimension stone and brick provide examples of the suitability of microRaman spectroscopy to analysing the processes and transformations of natural materials, for industrial benefit. The potential to enhance the technique became evident and a gemstone macrochamber and 'well-plate' - type sample holder constructed to realise this. Circularly polarised light was investigated for collecting orientation-independent spectra.;The ability to collect structural information over a micrometer scale in the form of maps and images makes the technique attractive to mineralogists. Lack of sample preparation, disparity of sample type and sensitivity are all advantages over XRD, a favoured technique in the investigations considered.;MicroRaman spectroscopic study of minerals has been found to have few limitations. Notably, these are largely unpredictable fluorescence and potential for ambiguity of results. The technique has great prospects in the Earth Sciences and will become a routine analytical method.