Abstract
The ordered arrangement of carbon vacancies in vanadium carbides near V6C5 has been analysed by means of selected-area electron diffraction and high-voltage electron microscopy. A new type of ordered distribution of carbon vacancies is found at non-stoichiometric compositions between V6C5 and V8C7. This structure can be expressed as a longperiod structure consisting of the enantiomorphic domains based on the structure V6C5 which was determined by Billingham. Bell and Lewis (1972). The periodic domain boundaries with spacing eleven times the nearest-neighbour interatomic distance are directly observed by electron microscopy.