Stabilisation of ions in unusual oxidation states and electron dynamics in oxide glasses

The results of studies on the stabilisation of ions in unusual oxidation states in oxide glasses are summarised. Special attention is given to the connection of such ion stabilisation with the processes of electron density transfer, and to the disproportionation reactions. The effect of reversible low-temperature disproportionation on niobium, titanium, vanadium, molibdenium, tungsten ions ets. is treated. The formation of metal clusters in glasses is also shown to be connected with disproportionation.