Dielectric investigations of La-doped barium titanate

Abstract

In the present paper results of the dielectric investigation of barium titanate (BaTiO3) doped with different concentrations of lanthanum are presented. Ceramic samples were prepared by the Pechini process. With increased doping the grain size of ceramics decreases from 2.5 μm in pure samples down to 0.2 μm in 0.5 mol% La - doped BaTiO3. Ceramics showed maximally enhanced dielectric permittivity around low-, room and hightemperature phase transitions, which are the phase transitions of the pure BaTiO3. The Curie temperature, TC, is lowered by 30 K with increase of doping concentration to 0.5 mol% La. Dielectric spectra revealed three parts: low frequency part which is caused by conductivity process, middle frequency relaxational process part and high frequency relaxational/polar modes contribution.