Excellent stability and low dielectric loss of Ba(Fe0.5Nb0.5)O3 synthesized by a solution precipitation method

• The solution precipitation method could reduce the calcination temperature of the BFN powders to a low temperature (1223 K).
• The solution precipitation method could significantly reduce the dielectric loss of BFN ceramic. The frequency stability and temperature stability can also significantly improved.
• The complex impedance analysis provide more effective exidence of the high dielectric constant supported by the grain boundary barrier layer capacitor model.

A solution precipitation method was applied to prepare Ba(Fe0.5Nb0.5)O3 powders. Nano-size BFN powders with uniform particles size (∼40 nm) were synthesized by solution precipitation method, which is beneficial to calcine at low temperature (1223 K). The sintering sample with dense microstructure and uniform grain size (15 μm) was obtained at 1673 K, which exhibits enhanced dielectric properties. The dielectric loss of BFN ceramic could be significantly reduced by solution precipitation method. The frequency and temperature stability of BFN ceramics could also be improved. The complex impedance spectroscopy analysis results suggested that the obtained Ba(Fe0.5Nb0.5)O3 ceramics, consisting of semiconducting grains and insulating grain boundaries, were electrically heterogeneous. The grain boundary effect was responsible for such a high value of dielectric constant.

Frequency dependence of dielectric constant and dielectric loss for BFN ceramics prepared by the solution precipitation method and solid–state reaction method between 100 Hz and 1 MHz. The low dielectric loss and high dielectric constants of BFN ceramics could be obtained by solution precipitation method.Figure optionsDownload as PowerPoint slide