Dielectric behavior and microstructure of (Bi[sub ½]Na[sub ½])TiO₃-(Bi[sub ½]K[sub ½])TiO₃-BaTiO₃ lead-free piezoelectric ceramics

Abstract

(0.95−x)(Bi[sub ½]Na[sub ½])TiO₃-x(Bi[sub ½]K[sub ½])TiO₃-0.05BaTiO₃ 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 ε[sub r] 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.