Reaction-sintering of lead-free piezoceramic compositions: (0.95 − x)Na0.5K0.5NbO3–0.05LiTaO3–xLiSbO3

Incorporation of LiSbO3 into the lead-free piezoceramic composition 0.95Na0.5K0.5NbO3–0.05LiTaO3 produced a change from an orthorhombic to tetragonal crystal system in samples produced by reaction-sintering. The inferred limit of solid solution along the compositional join, (0.95 − x)Na0.5K0.5NbO3–0.05LiTaO3–xLiSbO3, occurred at x ~ 0.06. Differential scanning calorimetry indicated broad peaks at temperatures associated with ferroelectric–paraelectric transitions. The transition temperatures decreased with increasing values of x, up to x = 0.06. Microstructures showed secondary grain growth; a slight decrease in grain-size with increasing LiSbO3 modification was identified.