On the Structure of Glass

JSGT 1951 V35 T411-T420

The paper analyses the general conditions for the formation of glasses, considered as polymer states with rigid irregular frameworks. Local stability of such equilibrium states demands mixed chemical bonding forces which are partly covalent and partly of ionic nature. Large-scale stability restricts the types of irregularity allowed. Particle co-ordination numbers are generally two, three or four only, and polymer coherence is effected substantially by bridging atoms of the eight-electron type. The bonding type of a substance in a glassy state may differ fundamentally from that of its crystalline state; in this case special methods may be necessary to obtain the glass. The common oxide glass formers favour glass formation because of the peculiarity that their undercooled melts develop no other than the bonding types needed for their glassy states.

Adolph G. Smekal