Glass ceramics with ferroelectric crystalline phases

Obtaining a glass ceramic via devitrification of a fully amorphous glass phase leads to a pore-free material, in which crystallites with their ferroelectric phase are embedded in a residual glass matrix. This matrix in turn forms a close-to-ideal dielectric. Such a structure offers, in principle, several advantages over conventional sintered ceramics, particularly with respect to ageing and fatigue. We show examples of ferroelectric glass ceramics in which the composition of the ferroelectric phase as well as the size of the crystallites are varied in a systematic way. The dielectric and structural properties are discussed in detail.