Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties

Quantitative electron energy-loss spectroscopy microanalysis of platelet and voidite defects in natural diamond

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Chemical analysis of ‘voidites’ in diamond reveals only nitrogen, whereas similar analysis of ‘platelets’ shows no detectable nitrogen. The method of analysis is electron energy-loss spectroscopy in a dedicated scanning transmission electron microscope. The voidite size ranges from 2 to 5 nm. The results suggest that the voidites arise from discontinuous precipitation of nitrogen on dislocations including dislocations bounding the platelets. The nitrogen in the voidites is very dense (one-half the atomic density of the diamond) and it seems probable that the diamonds are formed somewhat deeper in the Earth's mantle than previously estimated. © 1989 Taylor & Francis Group, LLC.