Multinuclear magnetic resonance study of Li 2 OSiO 2 SolGel glasses

A multinuclear magnetic resonance study of some solgel prepared Li 2 OSiO 2 glasses and of their crystallization is presented. The glasses, all of which have been heated to 400°C, are found to contain a large amount ( ca. 20 mol‐%) of H 2 O, mostly in the form of OH. The local structure is very different from melt‐formed glasses in that the major modifier is H 2 O rather than Li 2 O, with the formation of Si(OSi) 3 OH units. The glasses start to crystallize at a lower temperature than melt‐formed glasses, with the first crystalline product being lithium metasilicate even for very silica rich sol‐gel compositions.