Structure And Properties Of Ba²⁺,Nd³⁺ Doped PSN-PZT Piezoelectric Ceramics

Lead-based piezoelectric ceramics have been dominated the commercial market in actuators and transducers for several decades due to their excellent piezoelectric performance.With the continuous progress and development of science and technology,they cannot satisfy the imperious demands in the high temperature industrial applications,such as deep oil drilling rigs and aerospace explorations.In recent years,because of carbon dioxide passes by the use of conventional fuel,more and more countries have begun to pay significant attention to the environmental problem caused by the destruction of the ozone layer.A number of researches on piezoelectric energy harvesting which is able to convert mechanical energy and electrical energy into each other have been investigated to settle the problem.An important parameter to evaluate the piezoelectric energy harvesting is conversion efficiency between mechanical and electrical,which is closely related to the electromechanical coupling coefficient of piezoelectric materials.Based on the above considerations,it is a significant task for researchers to search a new material with high piezoelectric properties to meet the severe requirements on commercial applications.In this paper,0.02Pb(Sb_0.5Nb_0.5)O₃-0.98Pb?Zr,Ti?O₃?abbreviated as PSN-PZT?is selected as the research object,the following researches was conducted.?1?Ba²⁺doping PSN-PZT piezoelectric ceramics:air as the sintering atmosphere,Zr/Ti=52/48 PSN-PZT piezoelectric ceramics as the object material,and research the ceramics of A-site Pb²⁺replaced with Ba²⁺.The results show that,ceramics with Ba²⁺content of 4mol%have best piezoelectric performance,Curie temperature T_c=324?,piezoelectric coefficient d₃₃=502p C/N,electromechanical coupling k_p=0.85,at the range of 0?100?,the maximum fluctuation of k_p was 5.0%.?2?Ba²⁺doping PSN-PZT piezoelectric ceramics:PSN-PZT?Zr/Ti=52/48?ceramics with Pb²⁺replaced by Ba²⁺at oxygen sintering atmosphere.During this work,XRD crystal structure analysis showed that the structure of all samples was tetragonal at room temperature.The content of Ba²⁺did not significantly change the crystal structure of the sample.The GSAS refinement result showed that the tetragonality of the sample was gradually reduced.The test results about electrical and piezoelectric properties showed that the ceramics has the best performance when the Ba²⁺content was 5mol%,the residual polarization intensity P_r=34.6?C/cm²,the coercive field strength E_c=16.2k V/cm,piezoelectric coefficient d₃₃=560p C/N,Curie temperature T_c=317°C,strain S=0.19%,and strain hysteresis H=0.178%.?3?Nd³⁺doping PSN-PZT piezoelectric ceramics:the XRD results showed that all the samples possess tetragonal structure at room temperature and the amount of Nd³⁺has little effect on the crystals structure.The test results of electrical and piezoelectric properties showed that the sample has a prominent electromechanical coupling coefficient k_p=0.82 when Nd³⁺content was 1 mol%,at the same time the coercive field strength E_c=17.0k V/cm,the residual polarization intensity P_r=40.0?C/cm²,the piezoelectric constant d₃₃=463p C/N,and the Curie temperature T_c=331?,during the temperature range of-50?150?,the maximum fluctuation of k_p was 7.4%.