【作者】 唐波；

【导师】 樊慧庆；

【作者基本信息】 西北工业大学 ， 材料学， 2006， 硕士

【摘要】 本研究系统论述了La元素掺杂对PLZT铁电陶瓷的微观结构及电性能的影响,解释了La元素含量变化对一组穿越准同型相界（MBP）的化学组分的PLZT铁电陶瓷微观结构演化机理的影响,建立了PLZT铁电陶瓷微观结构与电性能之间的关系,并采用传统的固相反应烧结工艺成功制备了高质量的准同型相界铁电陶瓷4/56/44PLZT。在这一工作的基础上,又通过Fe³⁺离子掺杂PLZT起到的电位补偿效应对La元素掺杂导致的PLZT铁电陶瓷晶格的过分畸变进行一定程度的调节,使得烧结得到的陶瓷晶粒更为均匀和细小。另外,利用准同型相界铁电陶瓷4/56/44PLZT的光生伏特智能效应,进行了应用技术的理论探索,成功建立了微小型光电马达的模型,并从理论上验证了马达的可行性。 首先,通过传统的直接化学反应法制粉,并结合冷等静压技术（CIP）压片,采用PbZrO₃气氛粉埋烧的固相反应烧结工艺,成功制备了Pb_1-xLa_x(Zr_0.56Ti_0.44)_1-x/4O₃（x=0.02,0.04,0.06,0.08,0.10,0.12,0.125）系列陶瓷,对其进行了XRD、SEM、介电测试、温谱测试及部分压电测试。经分析得出了La元素掺杂含量对PLZT陶瓷结构和电性能的影响关系,成功建立了PLZT铁电陶瓷微观结构演化机理与陶瓷电性能之间的关系模型。 其次,开展了Fe³⁺离子掺杂PLZT的制备,着重研究了Fe元素掺杂含量变化对Pb_0.96(La_1-zFe_z)_0.04[Zr_0.56Ti_0.44]_0.99O₃陶瓷微观结构和电性能的影响,以及烧结时间对陶瓷微观结构和电性能的影响。研究表明,Fe元素掺杂起到了电位补偿效应,对La元素掺杂导致的PLZT铁电陶瓷晶格的过分畸变在一定程度得到了调节,使得晶粒尺寸减小,晶粒分布更为均匀。其中Fe元素含量为3.6mol%时,在烧结时间均为2h条件下,制得的试样具有最高的密度和最小的晶粒尺寸,且粒径分布最均匀。在掺杂Fe元素矫正晶格畸变的同时,使得陶瓷的介电常数和介电损耗在较宽频率范围内减小。对烧结时间参数的研究结果表明,烧结时间为2h制得的系列陶瓷试样均具有最好的致密度。 最后,通过理论分析和有限元模拟论证了以光生伏特效应作为驱动的微小型光电马达的可行性,成功建立了微小型光电马达的理论模型和设计模型。更多还原

【Abstract】 Microstructure evolutions and electrical properties of Pb_1-xLa_x(Zr_0.56Ti_0.44)_1-x/4O₃ （x=0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.125） ceramics with the La content increasing have been investigated, because these compositions are across the morphotropic phase boundary （MBP） area in the phase diagram of the PLZT solid-solution system. This research explains the influence of La content changing on the microstructure evolutions of the PLZT traversing the chemistry compositions of the morphotropic phase boundary （MBP）, and establishes the relationships between microstructure evolutions and electrical properties of the PLZT. The high quality samples 4/56/44PLZT which were prepared by a conventional mixed oxide method followed by burying sintering in PbZrO₃ powder under air atmosphere have been obtained. Furthermore, Fe³⁺ modified PLZT ceramics were prepared and characterized. Fe³⁺ ions can compensate the electric charges produced by the crystal lattice aberration, which makes the size of the PLZT ceramics grains smaller and the structure more compact. Otherwise, making use of the characteristic of the PLZT ceramics of the MBP compositions which can change photic energy to electrical energy, this paper carries through the theory investigation of the application technology, hence model of the photoelectric micro-motor has been founded, and the feasibility approved theoretically successfully.The high purity PbO, La₂O₃, TiO₂ and ZrO₂ were as starting powder, the research adopted the solid-reaction method to gain the PLZT raw powder. Then the PLZT raw powder were cold uniaxial pressed with a definite pressure into cylindrically shaped specimens. Then the specimens were cold isostatically pressed at high pressure. The Pb_1-XLa_x(Zr_0.56Ti_0.44)_1-x/4O₃（x=0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.125） ceramics were synthesized using a high-temperature solid-state reaction technique. Then X-ray diffraction investigation, microstructure, dielectric properties of the ceramics are carried out. For all sets of samples the variation of La content induces changes in the physical properties. Otherwise, the mechanism of the microstructure evolutions of PLZT ceramics is discussed.The research of Fe³⁺ adopted the PLZT ceramics focused on the influences of iron element content increasing on the microstructure evolutions and dielectricproperties, including the experimental parameter of sinter time. The results investigated that the iron element adopted in the PLZT ceramics makes an part in compensating the electric charges produced by the crystal lattice aberration and reducing the size of the grains. With the iron element content increasing to 3.6mol%, the gained samples with sintering under identical conditions （burying into PbZrCb powder, 1250°C, 2h, air atmosphere） have the highest densities and the least size of grains. On the other hand, the iron element leads to decreasing of the dielectric constant and the dielectric loss, while the iron ions compensated the electric charges produced by the crystal lattice aberration. The results indicated the perfect experimental parameter of sinter time is two hours. Under this condition, the gained ceramics have the highest densities.In addition, the other part research work focused on found of model of the photoelectric micro-motor, and the feasibility approved theoretically successfully in theory by using FEA （finite elements analysis） method.更多还原