Influence of reduction process on the structural and mechanical properties of (Pb,Bi)-(Si,Ge)-O oxide glasses

The effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some granules of metallic bismuth with a diameter of tens to hundreds of nanometers were formed on the surface of the glass. Furthermore, depletion of lead was observed in these samples in relation to the initial stoichiometry of the glass prior to trial reduction