Study On Modification Of PAT Based Piezoelectric Ceramics

With the development of piezoelectric ceramics toward miniaturization,energy saving and intelligence,its application fields will be further discovered and expanded.In recent years,the development of biomedicine has also drawn attention to materials researchers.Cold plasma can promote wound healing,treat tumors,destroy various bacterial fungi,and be used in medical aesthetics,so research on ceramic materials for cold plasma emitters has become a trend.Studies have shown that Pb(Mn_1/3Sb_2/3)O₃-PZT（PMS-PZT）ternary piezoelectric ceramics with a perovskite structure have both a high mechanical quality factor（Q_m）and a high electromechanical coupling coefficient（K_p）.This thesis is based on the research object of PMS-PZT ternary piezoelectric ceramics,and then it is modified by doping.0.05Pb(Mn_1/3Sb_2/3)O₃-0.48Pb Zr O₃-0.47Pb Ti O₃piezoelectric ceramics were prepared by solid-phase reaction method.The effects of different sintering temperatures on the phase structure,microstructure and electromechanical properties of piezoelectric ceramics were studied.The study found that PMS-PZT ceramics have a perovskite structure and a very pronounced dielectric relaxation behavior;Ceramics perform best near the morphotropic phase boundary;When the calcination temperature is 800℃and the sintering temperature is 1150℃,the comprehensive properties of ceramics are the best:d₃₃=214p C/N,K_p=0.56,Q_m=1715,ε_r=1217,tanδ=0.0065,T_C=349℃.This article will use this basic formula as the basis for research on doping modification of piezoelectric ceramic systems.In order to further improve the Q_mof PMS-PZT ceramics,Fe₂O₃was doped in PMS-PZT ceramics.Through the study of the microstructure and electromechanical properties of Fe₂O₃-doped PMS-PZT ceramics,it is found that Fe-doped PMS-PZT ceramics have a perovskite structure,and at the same time it is conducive to the increase of the ceramic grain size and make the ceramics dense;While reducing the sintering temperature,it also enhances the electromechanical properties of various items;A moderate amount of Fe-doped PMS-PZT ceramics exhibits"hard"doping performance characteristics.When Fe₂O₃is doped at 0.5wt%and the sintering temperature is 1100℃,the sample has the best electrical properties:d₃₃=333p C/N,K_p=0.60,Q_m=1807,ε_r=1475,tanδ=0.0142,T_C=326℃.Based on the above studies,Bi₂O₃was doped in PMS-PZT-0.5wt%Fe₂O₃,and its effects on the microstructure and electromechanical properties of piezoelectric ceramics were studied.It was found that doping a proper amount of Bi into PMS-PZT-0.5wt%Fe₂O₃reflects"soft"doping,which reduces the sintering temperature and enhances the Kp.The best comprehensive properties are obtained when the doping amount is 0.5wt%and the sintering temperature is 950℃:d₃₃=280p C/N,K_p=0.66,Q_m=1781,ε_r=1681,tanδ=0.0056,T_C=338℃.