Effect Of PZT-based Piezoelectric Ceramics On Element Control And Modification Doping On Electromechanical Coupling Coefficient

Piezoelectric ceramic materials have been developed to date and have been widely used in many fields of modern society,which greatly facilitates people's production and life.Although the application technology of piezoelectric ceramic materials is very mature,people's craving for high-performance piezoelectric ceramic materials is getting stronger and stronger.The development of high-performance piezoelectric ceramic materials with high-voltage electrical constants and high electromechanical coupling coefficients is one of the most important research directions.In this paper,the traditional solid phase sintering method widely used in industry will be adopted.PSN-PMS-PNN-PZT multi-component PZT-based piezoelectric ceramics is used as the matrix material.The introduction of new components,comparison of sample adjustment and trace element doping are systematically studied.The effects of heterogeneous methods on phase structure,microstructure,piezoelectric properties,dielectric properties and hysteresis loops of ceramic samples.High-performance PZT-based piezoelectric ceramic materials with high-voltage electrical constant,high electromechanical coupling coefficient,low dielectric loss and low mechanical quality factor were prepared.It is possible to promote the application of this type of piezoelectric ceramic formula in electroacoustic and actuators such as buzzers,alarms,speakers,and Jacquard combs.The details are as follows:?1?Firstly,a new component PSN is introduced on the basis of PMS-PNN-PZT low-loss PZT-based piezoelectric ceramics to form a new PSN-PMS-PNN-PZT piezoelectric ceramic solid solution.By changing the amount of introduction of the PSN component,the best performance point is found.The results show that the solid solubility of PSN component in ceramic system is less than 3 mol%.When the introduction amount of PSN reaches 3 mol%or more,a significant pyrochlore phase is formed in the ceramic system.However,proper introduction of PSN components can significantly increase the electromechanical coupling coefficient and piezoelectric constant of ceramic samples,while the dielectric loss does not increase significantly.When the PSN content is 1 mol%,the ceramic has the best comprehensive performance:d₃₃=875 pC/N,k_p=0.66,?_r=6653,tan?=1.1%,Q_m=75,T_c=114.6?,?=1.9559,P_r=26.66?C/cm²,E_c=3.42 kV/cm.?2?Secondly,under the premise of fixed PSN component and PMS component content,the effect of PNN/PZT ratio on PSN-PMS-PNN-PZT piezoelectric ceramics was changed.Studies have shown that changing the PNN/PZT ratio to some extent does not produce other phases.When PNN/PZT=0.49/0.49,the ceramic sample has the best comprehensive performance:d₃₃=881pC/N,k_p=0.66,?_r=6764,tan?=1.1%,Q_m=74,T_c=118.9?,?=1.9450,P_r=26.46?C/cm²,E_c=3.40 kV/cm.?3?Study the effects of different PNN/PZT and Zr/Ti ratios on the quasi-homophase boundary and properties of ceramic samples.Studies have shown that an increase in the Zr/Ti ratio causes the characteristic diffraction peaks of the ceramic samples of the respective components to be shifted to a low angle to different degrees.The piezoelectric constant and electromechanical coupling coefficient of all samples increased first and then decreased as the Zr/Ti ratio increased.And when the proportion of PNN components in the system increases gradually,the degree of deviation of the ceramic samples from the quasi-homophase boundary can be reduced by changing the Zr/Ti ratio in the system.When PNN/PZT=0.45/0.53,Zr/Ti=0.33/0.67,the ceramic has the highest electromechanical coupling coefficient,and the ceramic is near the quasi-homophase boundary.The specific electrical performance parameters are:d₃₃=866pC/N,k_p=0.68,?_r=5777,tan?=1.07%,Q_m=91,T_c=133.6?,?=1.9578,P_r=25.44?C/cm²,E_c=4.17 kV/cm.?4?Finally,the effect of trace element modified doping on PSN-PMS-PNN-PZT multi-component piezoelectric ceramics was studied.The results show that the Ce3+doped ceramic samples undergo a significant phase transition,and the doping amount increases the internal transformation of the ceramic from the tetragonal phase to the tetragonal phase,and at the same time can make the grain development better.Through the doping of Ce⁴⁺,the ceramic sample has the best MPB structure when the doping amount is 0.2wt.%,and the electromechanical coupling coefficient of the ceramic sample is further improved.The specific parameters are as follows:d₃₃=879pC/N,k_p=0.70,?_r=6303,tan?=0.92%,Q_m=70,T_c=123.9?,?=1.9726,P_r=23.64?C/cm²,E_c=3.85kV/cm.