Characterization of lead-free B<inf>2</inf>O<inf>3</inf>doped barium stannate titanate ceramics

Abstract

Lead-free barium stannate titanate ceramics doped with 2 wt% of B2O3were prepared via a solid state sintering. The optimum condition for the preparation was carried out. Properties of the lead free material were characterized by various methods. The high dielectric constant >14000 with low tanδ 0.040 was observed at 34°C for the samples prepared at the optimum condition. Plots of dielectric permittivity as a function of temperature showed that the ceramics exhibit a diffuse ferroelectric - paraelectric phase transition. The dielectric constant was also measured as a function of electric field. The dielectric- electric field measurement indicated that this material exhibits a high tunability. In addition, mechanical property such as hardness was investigated. Relation between grain size and hardness of the ceramics was found to obey the Hall-Petch equation: Hv0.07 + 12.9G1/2. © 2009 American Institute of Physics.