LA2TI2O7 CERAMICS

La2Ti2O7 powders were prepared using three different techniques. Single-phase material was obtained at 1150-degrees-C by calcination of mixed oxides, at 1000-degrees-C by molten salt synthesis, and at 850-degrees-C by evaporative decomposition of solutions. Particle sizes and morphologies of the powders differed substantially, as did the sintered microstructures and dielectric properties. Very dense (99%), translucent, grain-oriented lanthanum titanate was fabricated by hot-forging at 1300-degrees-C under a 200-kg load. Anisotropy was demonstrated by X-ray diffraction, scanning electron microscopy, thermal expansion, and dielectric measurements.