A study of atomic structure of glassy materials

Glassy materials have applications in a variety of fields. The composition of these materials can be varied easily and so tailored to particular applications. To improve the design of materials an understanding of the atomic structure is required. Herein, several materials have been studied each wit...

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Bibliographic Details
Main Author: Smith, Jodie Melissa
Published: University of Kent 2013
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633701
Description
Summary:Glassy materials have applications in a variety of fields. The composition of these materials can be varied easily and so tailored to particular applications. To improve the design of materials an understanding of the atomic structure is required. Herein, several materials have been studied each with a different rationale. The technique of neutron diffraction has been employed to elucidate the atomic structure; with other techniques used to further the understanding of the structure. Amorphous calcium gallate was studied primarily because it contains no traditional glass formers. The gallium environment is of interest as it acts as a networker former within this material. The material was synthesised using a novel method of laser heating with aerodynamic levitation. The system was studied using neutron diffraction, molecular dynamic modelling and high field magic-angle-spinning NMR (MAS-NMR). A calcium phosphate based glass has been studied to determine the effect of increasing aluminium content on the atomic structure, using neutron diffraction and MASNMR. This allowed the interesting trend in the material properties, with increasing aluminium concentration, to be linked to the local environment of the aluminium. Bioglass ®, a commercial product to regenerate tissue, has been doped with transition metals, the local environment of which is critical to determine the suitability of this addition. Neutron diffraction with isotopic or isomorphic substitution enabled the study of the local environment of these elements. The effect of substituting strontium for calcium was studied in a material which has a similar composition to several commercial biomaterials. The -materials were studied using neutron diffraction to reveal information regarding changes in crystallisation as a result of the strontium substitution. Finally the potential of the unique NIMROD instrument is explored, using data collected from several silica based sol gel materials including a titanium silicate series and a calcium silicate series.