Molybdenum nonstoichiometric oxides

The existence of at least nine phases in the molybdenum-oxygen system is well established. Their crystal structures are briefly described and it is shown that they can be classified into four main families dependent on whether they possess a basic structure of rutile type, ReOs type, or MoOs type, or have complex structures where polygonal networks can be distinguished. The known tungsten and mixed molybdenum tungsten oxides fit into this scheme. Because of their complicated formulas many of these compounds may be termed "nonstoichiometric," but variance in composition has not been observed for any of them. 

Many molybdenum and tungsten oxides are known. The simple ones are Mo03, W03, Mo02, and W02. Other, nonstoichiometric, oxides have been characterized and have complicated structures. 

Like molybdenum and tungsten, vanadium forms a variety of nonstoichiometric oxides with the alkali metals and other cations, for example, Cu+, Ag+, Zn+, or Al+, which have bronze-like properties. " These compounds can be made by heating appropriate mixtures of V2O5 and the desired alkali metal carbonate or oxide in platinum vessels under argon at 700-800 °C and then cooling slowly over... 

The electrochemical behavior of nonstoichiometric molybdenum oxides M0O3 5 suggests that both charmel/site size and electronic conductivity are the predominant factors influencing the extent of reversible lithium incorporation by metal oxides with framework structures shear-related to those of Re03 and M0O3. Distortions and nonequivalence of the sites available for LU accommodation should affect the thermodynamics of the reduction processes. The nonstoichiometric... 

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