Non-stoichiometry in metallic monoxides

An interesting group of non-stoichiometric oxides are the transition-metal monoxides (MO, where M = metal) for example, titanium monoxide (TiO) and vanadium monoxide (VO). These have a wide range of non-stoichiometric 

2 Long-range order and elimination of point defects 

Even at lower concentrations (10 ), some interactions between point defects are possible. In forming new structures, the vacancies either order or they are eliminated. These vacancy accommodation processes are immensely important in heterogeneous oxidation catalysis using oxides and we examine these in the following sections. 

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