STILLWELLITE GLASS-CERAMICS WITH FERROELECTRIC PROPERTIES

The process of crystallization of LaBGeO5 and PrBGeO5 phases with stil lwellite structure from the glassy state is studied. Exotherms on diff erential thermal analysis curves for lanthanum borogermanate glasses a re interpretated by using the X-ray diffraction and the second harmoni c generation method data. It is shown that acentric nuclei of the stil lwellite phase are formed at the early stages of crystallization. Ther e is not any metastable phase, prior to stillwellite precipitation. Gl ass-ceramic samples with high stillwellite content were synthesized, a nd their properties were measured and compared with the properties of a single crystal of LaBGeO5.