Effect of a Metastable Precipitate on the Electrical Properties of an Li 2 ,O‐SiO 2 Glass

Glass structural differences in a 17.5 wt% (30 mole %) Li 2 O‐SiO 2 glass resulting from thermal treatments in the annealing‐transformation range were studied using electron microscopy, X‐ray analysis, and dc and ac electrical properties. Metastable, crystalline lithium metasilicate precipitates and subsequently redissolves prior to the appearance of the equilibrium lithium disilicate crystals. The lithium metasilicate gives rise to dielectric loss peaks in the 100 hz to 1 Mhz range which can be rationalized on the basis of the Maxwell‐Wagner‐Sillars heterogeneous dielectric model.