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Title: Correlation between layer thickness and periodicity of long polytypes in silicon carbide

Abstract

The layer widths and repeat spacing of long-period polytypes (LPPs) have been determined using synchrotron radiation source (SRS) X-ray diffraction topography (XRDT). This method has proved to be a powerful tool in investigating the spatial extent of one-dimensional disorder (1DD), long-period polytypes (LPPs) and the boundaries of polytype layers in silicon carbide (SiC). The resulting neighbourhood coalescence models have confirmed the validity of the sandwich rule even in the limit of two arbitrarily long LPPs, as well as the unique nature of the 6H polytype. A significant empirical trend is reported here that relates the thickness of LPP layers to the periodicity of the repeat stacking sequence measured on the topographs. A good correlation between the data suggests that this behaviour is governed by a simple mathematical expression t = kN {sup n}. Values for k and n have been determined that relate the polytype thickness (t in microns) to the number of hexagonal layers (N) in the polytype stacking repeat. These values can be used to prompt questions about the limits of polytypism and disorder in SiC.

Authors:
 [1];  [1];  [1]
  1. Industrial Materials Group, School of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX (United Kingdom)
Publication Date:
OSTI Identifier:
20889729
Resource Type:
Journal Article
Journal Name:
Materials Research Bulletin
Additional Journal Information:
Journal Volume: 40; Journal Issue: 2; Other Information: DOI: 10.1016/j.materresbull.2004.10.008; PII: S0025-5408(04)00325-3; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0025-5408
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COALESCENCE; CRYSTAL GROWTH; LAYERS; PERIODICITY; SEMICONDUCTOR MATERIALS; SILICON CARBIDES; THICKNESS; X-RAY DIFFRACTION

Citation Formats

Kelly, J F, Fisher, G R, and Barnes, P. Correlation between layer thickness and periodicity of long polytypes in silicon carbide. United States: N. p., 2005. Web. doi:10.1016/j.materresbull.2004.10.008.
Kelly, J F, Fisher, G R, & Barnes, P. Correlation between layer thickness and periodicity of long polytypes in silicon carbide. United States. doi:10.1016/j.materresbull.2004.10.008.
Kelly, J F, Fisher, G R, and Barnes, P. Tue . "Correlation between layer thickness and periodicity of long polytypes in silicon carbide". United States. doi:10.1016/j.materresbull.2004.10.008.
@article{osti_20889729,
title = {Correlation between layer thickness and periodicity of long polytypes in silicon carbide},
author = {Kelly, J F and Fisher, G R and Barnes, P},
abstractNote = {The layer widths and repeat spacing of long-period polytypes (LPPs) have been determined using synchrotron radiation source (SRS) X-ray diffraction topography (XRDT). This method has proved to be a powerful tool in investigating the spatial extent of one-dimensional disorder (1DD), long-period polytypes (LPPs) and the boundaries of polytype layers in silicon carbide (SiC). The resulting neighbourhood coalescence models have confirmed the validity of the sandwich rule even in the limit of two arbitrarily long LPPs, as well as the unique nature of the 6H polytype. A significant empirical trend is reported here that relates the thickness of LPP layers to the periodicity of the repeat stacking sequence measured on the topographs. A good correlation between the data suggests that this behaviour is governed by a simple mathematical expression t = kN {sup n}. Values for k and n have been determined that relate the polytype thickness (t in microns) to the number of hexagonal layers (N) in the polytype stacking repeat. These values can be used to prompt questions about the limits of polytypism and disorder in SiC.},
doi = {10.1016/j.materresbull.2004.10.008},
journal = {Materials Research Bulletin},
issn = {0025-5408},
number = 2,
volume = 40,
place = {United States},
year = {2005},
month = {2}
}