Sol-gel synthesis and characterization of Ce doped-BaTiO3

Barium titanate (BaTiO3 ) have been doped "in situ" with 5.5 mol% cerium by a sol-gel method using barium acetate, titanium (IV) isopropoxide, and cerium (III) acetylacetonate as starting materials. The dried gel showed a microstructure consisting of nano-sized grains ( ~ 140 nm) with great tendency to agglomeration. Several thermal analysis techniques were used to study the decomposition process of the gel. The presence of hydroxyls up to 720 °C suggests a strong bonding Ti OH that is responsible for the existence of aggregates even at high temperatures. The as-prepared gel powder was found to be amorphous, and then decomposes through oxides and barium carbonate around 500 °C and crystallizes on the perovskite structure of tetragonal BaTiO 3 at 1100 °C for 3h in air. A small influence of the frequency on the dielectric properties of the Ba 0.945 Ce 0.055 TiO3 ceramics was observed in 100 Hz to 1 MHz domain. At the Curie temperature point (22 °C) the dielectric constant was 10130 at 100 Hz while the dielectric loss (tan ? ) was 0.018.