Properties of lanthanum doped BaTiO3 produced from nanopowders

Pure and barium titanate (BT) powders doped with different lanthanum concentration were prepared by the polymeric precursor method (Pechini process) which was carried out as a three-stage process from organometallic complexes. Sintering of pressed powders was performed at 1300 °C for 2, 4 and 8 h. XRD analysis showed cubic BT powders with crystallite sizes between 20 and 25 nm and tetragonal crystal structure of BT ceramics. The influence of sintering time on grain growth was fairly obvious. It was found that lanthanum doping has significant effect on powders particle size and ceramics grain size. The influence of lanthanum concentration on grain size inhibition, improving the dielectric properties of BT ceramics was detected. The relation between sintering time, grain size, structure and electrical properties of the BT ceramics was analyzed.