Certain regularities of Si interaction with metal oxides

The systems of B2O3-Si, Al2O3-Si, Ga2O3-Si, In2O3-Si, TiO2-Si, Bi2O3-Si, V20:L5-Si, Mn2O3-Si, Sb2O3-Si have been studied. The most active and deep transformations take place in the systems of PbO-Si, Bi2O3-Si, and Sb2O3-Si. In the first two cases complete oxidation of silicon takes place with the formation of silicatoelement glasses. In the third system an intensive interaction has also been observed which weakens with time as a result of converting Sb2O3 into inert Sb2O4. Refractory oxides of In, Ga, Al, and Ti are inactive towards silicon. In the V2O5-Si system exchange interaction is thermodynamically possible but a change in a free energy for the reaction is smaller than for the case of Bi2O3 and PbO. It is noted that all transformations in initial oxides (dissociation, congruent evaporation, and polymorphic transformations) increase their activity in mixtures with silicon