Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649691
Title: X-ray diffraction by near-perfect crystalline surfaces
Author: Dower, C. Siobhan
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1994
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Abstract:
This thesis presents an investigation of the diffraction of x-rays by the types of disordered grating structure which are commonly present on near-perfect crystalline surfaces. Models to calculate the diffraction are developed with the intention of interpreting experimental measurements in terms of both the macroscopic grating structure and the atomic structure. The observability of interference effects from grating structures illuminated by partially coherent radiation is discussed. General kinematical expressions are developed describing the three-dimensional x-ray scattering profile associated with vicinal surfaces with terrace length disorder. Scattering profiles are calculated for specific examples of vicinal surfaces with statistically independent terrace lengths and correlations between terraces are discussed. The analysis of crystal truncation rod (CTR) intensities from vicinal surfaces is considered. The diffraction of x-rays by a reconstructed vicinal surface is investigated for the specific case of the Ge(001) (2x1) surface. It is proposed that an interference modulation of the reconstruction scattering can occur due to ordering in the registration of the reconstructed unit cells on different terraces; a model is developed to simulate the scattering profile. Subdomain structure due to lower symmetry reconstructions is also treated. Data from several Ge(001) surfaces is presented and interpreted in terms of the scattering models. An experimental study of the order-disorder c(4x2) → (2x1) phase transition in the Ge(001) surface reconstruction is described.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.649691  DOI: Not available
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