La ₂ Ti ₂ O ₇ Ceramics

Abstract

La 2 Ti 2 O 7 powders were prepared using three different techniques. Single‐phase material was obtained at 1150°C by calcination of mixed oxides, at 1000°C by molten salt synthesis, and at 850°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°C under a 200‐kg load. Anisotropy was demonstrated by X‐ray diffraction, scanning electron microscopy, thermal expansion, and dielectric measurements.