Dielectric behavior and microstructure of (Bi _1/2 Na _1/2) TiO ₃ - (Bi _1/2 K _1/2) TiO ₃ - BaTiO ₃ lead-free piezoelectric ceramics

(0.95-x) (Bi12 Na12) TiO3 -x (Bi12 K12) TiO3 -0.05 BaTiO3 lead-free piezoelectric ceramics (abbreviated as BNT-BKT-BT100x with x varying from 0 to 20 mol %) are prepared by a solid-state reaction process. Variation of the dielectric properties and microstructure of BNT-BKT-BT100x ceramics with BKT content is studied. The results indicate that the relative permittivity εr and loss tangent tan δ vary with the BKT amount. Scanning electron microscope observation also indicates that BKT in high amount affects the microstructure. X-ray diffraction analysis shows that the incorporated BKT diffuses into the BNT-BT lattice to form a solid solution during sintering.