Abstract: With the rapid development of scientific and technological level, the accuracy requirements for laser inertial navigation systems are becoming increasingly high. The quaternary PSN-PNN-PZT piezoelectric ceramics with large strain were prepared by the conventional solid-state synthesis method using industrial grade raw materials. The influence of different content Sr on the dielectric and piezoelectric properties of PSN-PNN-PZT piezoelectric ceramics was discussed. It is found that when the Sr content is 1% (mole fraction) and the molar ratio of n(Zr)/n(Ti) is 43/57, the PSN-PNN-PZT composition locates at morphotropic phase boundary and the piezoelectric ceramics show excellent properties. The large strain piezoelectric ceramics can be achieved, which are as follows: relative dielectric constant ε^T₃₃/ε₀=4 090, electromechanical coupling coefficient k_p=0.664, piezoelectric constant d₃₃=686 pC/N, dielectric loss tan δ=0.016 5, Curie temperature T_c=213 ℃. The strain of ϕ24 mm×ϕ5 mm×0.4 mm piezoelectric ceramic thin rings based on this material formula reaches 2.500 5 μm at 100 V driving voltage, which is 32.4% higher than that of the existing PZT-14 (P14) material. This material can be applied in high-precision laser gyro frequency stabilizers to improve the reliability of piezoelectric micro-displacement actuator。

Key words: piezoelectric ceramics, PSN-PNN-PZT, large strain, dielectric property, piezoelectric property, Curie temperature