Hydrothermal synthesis and dielectric properties of lanthanum titanate ceramics

Lanthanum titanate (La2/3TiO3) powders were synthesized by hydrothermal method based on the reaction of TiO2, La(NO3 )3 and KOH at 160 ℃ for 24 h followed by the treatment of acidification. The microstructure,morphology and dielectric properties were investigated by using X-ray diffraction, scanning electron microscope,transmission electron microscope and impedance method. The results show that the La2/3 TiO3 particles consist of nearly homogenous and lamellar grains. The particles can be sintered into porous ceramics above 1 150 ℃. The dielectric properties of La2/3 TiO3 show that both the dielectric constant and the dielectric loss tangent decrease with the increase of frequency.