Dielectric and Piezoelectric Properties of 0.97(Na 0.52 K 0.443 Li 0.037 )(Nb 0.96-x Sb 0.04 Ta x )O 3 –0.03(Bi 0.5 Na 0.5 ) 0.9 (Sr) 0.1 ZrO 3 Ceramics for Pizoelectric Actuator

In this study, 0.97(Na 0.52 K 0.443 Li 0.037 )(Nb 0.96-x Sb 0.04 Ta x )O 3 –0.03(Bi 0.5 Na 0.5 ) 0.9 (Sr) 0.1 ZrO 3 ceramics were fabricated as a function of Ta substitution by conventional solid state method in order to develop the excellent composition ceramics for piezoelectric actuator, and their dielectric and piezoelectric properties were investigated. As the chemical composition results of 0.97(Na 0.52 K 0.443 Li 0.037 )(Nb 0.96-x Sb 0.04 Ta x )O 3 –0.03(Bi 0.5 Na 0.5 ) 0.9 (Sr) 0.1 ZrO 3 system, we obtained the following results: When Ta was substituted for the ceramics, all the ceramics possessed a perovskite structure. When the substitution of Ta was 0, 0.01 and 0.02, Morphotropic phase boundary (MPB) region, which is coexist with rhombodedral phase and tetragonal phase was appeared. With further increasing the Ta substitution, the ceramics showed the strengthened tetragonal phase together with the coexistence of rhombodedral phase and tetragonal phase. The NKN-BNZ ceramics with x = 0.02 showed excellent piezoelectric properties. The density (ρ), piezoelectric constant (d 33 ), planar piezoelectric coupling coefficient (k p ), mechanical quality factor (Q m ), and dielectric constant (ε r ) were optimized as 4.456 (g/cm 3 ), 269 (pC/N), 0.419, 51, 1644, respectively.