Phase development, densification and dielectric properties of (0.95-x)Na_0.5K_0.5NbO₃ - 0.05LiTaO₃ - x LiSbO₃ lead-free piezoelectric ceramics

Abstract

Lead-free piezoelectric ceramics in the system (0.95-x) Na0.5K0.5NbO3 - 0.05LiTaO3 - x LiSbO3, x = 0-0.1, were synthesized by a reaction-sintering method. The effects of the content of LiSbO3, and the sintering temperature on phase-development, microstructure and dielectric properties of the samples were investigated. Additions of LiSbO3 produced a change in crystal system from orthorhombic to tetragonal. The additive reduced the temperature at which secondary recrystallisation occurred, and also affected average grain size and dielectric constant. A sintering temperature of 1050oC (for 2 h) was the optimum for this system in order to achieve a high density and high dielectric constant. A maximum dielectric constant of 1510 was recorded for the x = 0.04 composition.

Keywords

• lead-free material
• doping effect
• microstructure
• phase development
• dielectric properties