KNNS-BNKZ无铅压电陶瓷的制备及其电性能研究

The 0.96(K _0.48 Na _0.52 )(Nb _1-x Sb _x )O ₃ -0.04(Na _0.82 K _0.18 ) _0.5 Bi _0.5 ZrO ₃ (KNNS-BNKZ) lead-free piezoelectric ceramics were prepared by the direct synthesis and two-step synthesis method. The effects of different addition ways of the (Bi, Na, K)ZrO ₃ (BNKZ) and the amount of Sb on the microstructure and electrical properties of KNNS-BNKZ ceramics were studied. The results showed that the phase structure of KNNS-BNKZ ceramics prepared by direct synthesis method were tetragonal phase at room temperature, while the ceramics prepared by two-step synthesis were orthorhombic-tetragonal co-existence.The density,the dielectric constant ε _r ,the piezoelectric coefficient d ₃₃ of samples prepared by two-step synthesis method increased with the increase of Sb content, while the Curie temperature (T _C ) decreased. And the optimized electrical properties can be obtainedwhen the Sb content was 0.06, with ε _r of 1 659, tan δ of 0.038, T _C of 243 ℃, and d ₃₃ of 138 pC/N.