Ferroelectric sodium-potassium-niobium silicate glass-ceramics

Potassium niobate has been formed in potassium-niobium-silicate glasses containing /spl les/36 mol% silica. Solid solutions of (K/Na)NbO/sub 3/ have been obtained in heat treated sodium-potassium-niobium-silicate glasses containing 24 mol% silica. Although the dielectric constant of these glasses is strongly temperature dependent, it is probable that the dielectric behavior is due to the presence of residual glass and not the result of the presence of ferroelectric crystals. The glass-ceramics also contain a number of other, non-ferroelectric phases.