高电致应变无铅压电材料的制备研究

发布时间：2018-05-10 15:36

本文选题：无铅压电材料 + 场致应变　；参考：《上海师范大学》2015年硕士论文

【摘要】：半个多世纪以来,锆钛酸铅(PZT)基压电材料凭借其优异的压电与机电耦合性能,在驱动器、换能器、传感器等领域一直占据着主导地位。但由于PZT高的铅含量,对人体与环境构成巨大危害,发展新型的无铅压电材料来替代或部分替换传统铅基压电材料成为近些年来国内外研究热点之一。研究结果表明,(1-x)Bi0.5Na0.5Ti O3-x Ba Ti O3(BNT-BT,BNT-x BT)基压电材料在准同型相界(MPB)附近具有良好的压电性能,围绕MPB组分的BNT-BT进一步发展具有高场致应变无铅压电体系,引起了广泛的研究兴趣。第一原理计算表明,Bi(Zn0.5Ti0.5)O3(BZT)和Zn Sn O3(ZS)作为新型的无铅材料体系,理论上具有优良的铁电性能,由于纯BZT和ZS用常规方法难于合成,探索其它途径从实验上获得这些新的无铅材料体系具有重要意义。本论文中将这些第一原理计算的体系与现有的高性能无铅体系进行复合,通过制备固溶体的方法来得到具有纯的相结构的新材料体系,如将BZT与二元Bi0.5Na0.5Ti O3-Ba Ti O3(BNT-BT)进行复合,制备了BNT-BT-BZT(BNT-BTx BZT)固溶体系;将ZS与Ba Ti O3复合,制备了BT-ZS二元固溶体体系。研究结果表明,BNT-BT-BZT固溶体系均形成纯的钙钛矿结构,BZT的引入诱导了室温附近的相结构由铁电四方相向赝立方转变,同时伴随着大的场致应变,BZT浓度为5%mol时,体系在室温相对较低的电场强度下(4 k V/mm),获得的场致应变为0.23%,相应的等效压电系数(Smax/Emax)达到526 pm/V,显著地高于当前主要的BNT基无铅材料,场致应变在25-120 oC范围内表现出良好的稳定性。另外,该体系表现出极好的抗疲劳性,表明该三元固溶体系非常适合环境友好型驱动器的应用。BT-ZS固溶体系在x=0-0.10组分范围内均可形成纯的钙钛矿结构,ZS的引入诱导了室温附近的相结构由铁电四方相向立方相转变,伴随着大的电致伸缩响应。ZS浓度为10%mol时,体系在室温电场强度为4 k V/mm条件下,电致伸缩系数Q达到0.0452 m4C-2,优于传统的电致伸缩材料体系Pb(Mg1/3Nb2/3)O3,并且在25-120 oC表现出良好的稳定性,非常适合固态驱动器与执行器的应用。
[Abstract]:For more than half a century, lead zirconate titanate PZT-based piezoelectric materials have been playing a leading role in the fields of actuators, transducers and sensors because of their excellent piezoelectric and electromechanical coupling properties. However, due to the high lead content of PZT, it is a great harm to human body and environment, so the development of new lead-free piezoelectric materials to replace or partially replace the traditional lead-based piezoelectric materials has become one of the research hotspots at home and abroad in recent years. The results show that the piezoelectric properties of BNT-BTX BNT-BT3BNT-BNT-x based piezoelectric materials are good near the quasi-homogenous phase boundary. The further development of BNT-BT with high field-induced strain and lead-free piezoelectric system around the MPB component has attracted extensive interest. The results show that the piezoelectric materials based on the 1-xHX Bi0.5Na0.5TiO3-x BaTiO3- BNT-BTB-based materials have good piezoelectric properties near the quasi-homogenous phase boundary. The further development of the BNT-BT based on the MPB component has attracted extensive interest. The first principle calculation shows that Bi-Zn _ (0.5) Ti _ (0.5) O _ (3) BZT) and Zn _ Sn _ (3) O _ (3) ZS), as new lead-free materials, have excellent ferroelectric properties in theory. It is difficult to synthesize pure BZT and ZS by conventional methods. It is of great significance to explore other ways to obtain these new lead-free materials experimentally. In this paper, the first principle calculation system is combined with the existing high performance lead-free system, and a new material system with pure phase structure is obtained by preparing solid solution, such as BZT and binary Bi0.5Na0.5Ti O3-Ba TIO _ 3 BNT-BTs. The BNT-BT-BZT(BNT-BTx BZT solution system was prepared, and the BT-ZS binary solid solution system was prepared by combining ZS with BaTiO3. The results show that the introduction of pure perovskite structure in BNT-BT-BZT solid solution system induces the transition of phase structure near room temperature from ferroelectric tetragonal to pseudo-cubic, and at the same time, with the large field-induced strain and the concentration of 5%mol. When the electric field intensity of the system is relatively low at room temperature, the field-induced strain is 0.23, and the corresponding equivalent piezoelectric coefficient (S _ max / E _ max) is 526 pm / V, which is significantly higher than that of the main BNT based lead-free materials at present. The field-induced strain shows good stability in the range of 25-120 oC. In addition, the system shows excellent fatigue resistance, It is shown that the ternary solid solution system is very suitable for the application of environment-friendly actuator. The introduction of pure perovskite structure can be formed in the range of x ~ (0-0.10). The introduction of ZS induces the phase structure transition from ferroelectric tetragonal phase to cubic phase near room temperature. When the concentration of ZS is 10%mol, the electrostrictive coefficient Q is 0.0452 m4C-2 when the electric field intensity is 4 k V/mm at room temperature, which is superior to that of the traditional electrostrictive material system (PbmMg1 / 3Nb2 / 3Nb2 / 3O3), and shows good stability at 25-120oC. Very suitable for solid-state actuators and actuators.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ134.33

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