Dielectric properties of La2O3-doped Ba0.8Sr0.2TiO3 ceramics

La2O3-doped Ba0.8Sr0.2TiO3 dielectric ceramics were prepared by conventional solid state ceramic route. Scanning electron microscope was employed to observe the surface morphologies. The capacitance C and dielectric loss factor D of the samples were measured with automatic LCR Meter 4225 at 10 kHz respectively. The results show that: εr of the samples decreases and tgδ first decreases then increases with increasing amount of La2O3 doping. εr reaches better value, tgδ obtains the minimum value at 0.5 mol% La2O3. εr increases and tgδ decreases when sintering temperature increases. The samples doped with 0.5 mol% La2O3 sintered at 1,350 °C for 10 h exhibited attractive properties, including high relative dielectric constant (>4,000), low dielectric loss (16.8 × 10−4), low temperature coefficient of relative dielectric constant(<±21 %) in the temperature range of +25 to +85 °C.