Newly observed microscopic planar defects on {111} in natural diamond |
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Authors: | J. C. Walmsley A. R. Lang M.-L. T. Rooney C. M. Welbourn |
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Affiliation: | 1. H. H. Wills Physics Laboratory , University of Bristol , Tyndall Avenue, Bristol, BS8 1TL, England;2. DTC Research Centre , Belmont Road Maidenhead, Berkshire, SL6 6JW, England |
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Abstract: | Abstract Circular disc-crack-like defects randomly distributed on {111} planes have been discovered by 300kV transmission electron microscopy in diamond that had crystallized on non-faceted growth surfaces of mean orientation {100}. In a sample of ~ 100 defects, disc diameters were narrowly distributed about a mean of 1·2 μm and one in seven discs were located on a coplanar stacking fault of average diameter 2 μm. Discs totally enclosed within the specimen exhibit concentric moiré fringes covering their image areas when viewed obliquely, showing them to be dilated into thin lenticles. Internal pressures, deduced from moiré-fringe counts on six lenticles, were in the range 1·5 to 1·8 GPa. |
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Keywords: | Equivalent indentation radius Berkovich indenter finite element simulation average plastic strain |
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