Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486091
Title: Adsorption Studies on the i-Al70Pd21Mn9 quasicrystal
Author: Banks, Dominic
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2006
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Abstract:
Quasicrystals are of particular interest due to their tribological properties and potential use in technology. In particular the formation of single element aperiodically ordered overlayers is of great importance in modifying the surface properties. The initial effects of oxidation of the AIPdMn surface using pure water and molecular oxygen is reported here. The quasicrystal surface was dosed with either pure water or molecular oxygen until Auger electron spectroscopy (AES) indicated it had reached the point of saturation. Low energy electron diffraction (LEED) was employed to monitor the effects of the oxidation layer on the quasicrystal surface structure and found it was disrupted from low coverages. Scanning tunnelling microscopy (STM) was then used to investigate the surface in the saturation region and showed a highly disordered surface. X-ray Photoelectron spectroscopy (XPS) was used to investigate the electronic effects of adsorbing C60 onto the surface. The AI 2p, Pd 3d and C 1s core levels were investigated as well as the valence band to find out if any modification due to the adsorbate was evident at different ML coverages. It was found that no there was little effect to the AI and Pd core levels however the valence region was highly modified by C60. The C 1s core level shifted by a small expected amount. A Na overlayer previously investigated by STM has been interpreted using recent theoretical calculations of the clean and Na adsorbed quasicrystal su-rface. On first inspection the Na overlayer appears random and without order, however a diffraction pattern of a 0.8 ML covered surface found by FFT indicates otherwise. The theoretical model is tested and a possible explanation for the diffraction pattern is proposed.
Supervisor: Not available Sponsor: Not available
Qualification Name: University of Liverpool, 2006 Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.486091  DOI: Not available
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