High-resolution electron microscopy (HREM) images of niobium-doped tungsten trioxide show small spot contrasts and walls of apparently empty sites, in addition to a fascinating range of extended defects involving crystallographic shear, pentagonal column and combination precipitation phenomena. The precipitation of crystallographic shear defects in situ and the appearance of metal-rich surface layers are described. Computer simulations of pentagonal columns and of small-defect contrast are used to test the validity of oxygen-vacancy and interstitial-defect models, and to support the interpretation of more complex defect structures.
|Original language||English (US)|
|Number of pages||11|
|Journal||Proceedings of The Royal Society of London, Series A: Mathematical and Physical Sciences|
|State||Published - Jan 8 1988|
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