2. Glass composition

2.1 Why complicate the composition of a glass

While silica has the simple composition of silicon oxide, SiO ₂ , glasses, as we have seen, have a much more complex composition. Indeed, if the definition of a glass is that of a solid material with a non-crystalline structure, we know of many varieties, including purely metallic glasses. Some are obtained by hyperquenching, i.e. cooling a liquid metal so brutally that it solidifies in a few milliseconds. The lattice of atoms then has no time to rearrange itself into a crystalline structure, and remains disordered in the solid phase. But this process has no viscous phase, so there's no possibility of working the material in this phase as with conventional glass. However, by adding network-forming...