【作者】 鞠少功；

【导师】 唐新桂；

【作者基本信息】 广东工业大学 ， 材料物理与化学， 2012， 硕士

【摘要】 铁电陶瓷因其具有特殊的力学,热学,电学光学等性能或机,电,声,光,热,磁之间的耦合功能在电能量存储、能量转换、大位移致动器等领域中都得到广泛应用。在近十年来,人们的环保意识越来越强烈,无铅功能陶瓷受到更多的专家学者的重视。锆钛酸钡以及掺杂改性的锆钛酸钡基陶瓷的因为其具有优良的电性能和成熟的制备工艺而得到认可,如(Ba1-xCax)(Zr1-yTiy)O3(BCZT)及其掺杂。本文以传统的高温固相法制备了(Ba0.85Ca0.15)(Zr0.10Ti0.90)O3-xmol%Mn(0≤x≤0.5)的陶瓷以及溶胶凝胶法制备了(Ba0.90Ca0.10)(Zr0.25Ti0.75)O3薄膜,并研究了它们的电特性。对于120℃烧结的样品,从介温特性可以看出居里温度随着频率的增大而呈现驰豫特性,根据Maxwell Wagner理论和Vogel-Fulcher (VF)公式,得出其活化能Ea=1.15eV。增加烧结温度,最大介电常数有规律变化,最高可在烧结温度为1300C时达到9530。我们用居里外斯(修正)定律对陶瓷的介电常数随温度变化的规律进行了处理。BCZT样品都展现了很好的铁电特性,其剩余极化强度Pr和矫顽场Ec也随不同烧结温度分别呈现出一定的规律。压电性能也在1270℃烧结时最好,压电常数d33高达291pC/N。我们综合各项性能的测试得到在1270℃烧结的陶瓷的性能最好。为了解掺杂的二氧化锰对纯的BCZT陶瓷的性能的影响,我们按照(Ba0.85Ca0.15)(Zr0.10Ti0.90)O3-xmol%MnO2(x=0.1,0.2,0.3,0.4,0.5)制备了陶瓷并进行了一系列的研究。结果表明添加的烧结助剂Mn02对陶瓷的电性能有很大的影响。我们对不同锰离子掺杂量的陶瓷样品做了SEM,发现x≈0.3时,进入BCZT陶瓷晶粒的锰离子饱和,x>0.3后锰离子进入晶界。总体看锰离子的掺杂降低了BCZT陶瓷介电常数。根据修正的居里外斯定律,我们计算得到(Ba0.85Ca0.15)(Zr0.10Ti0.90)O3-x mol%MnO2(x=0.1,0.2,0.3,0.4,0.5)陶瓷的弥散性指数值Υ对应掺杂量x由小到大呈指数型增长。另外我们还对锰掺杂的BCZT的热释电性能做了一些研究,算出了他们的热释电系数。除此之外,我们采用传统的溶胶凝胶方法制备(Ba0.90Ca0.10)(Zr0.25Ti0.75)O3薄膜样品。我们测量了样品的结构、漏电流和铁电性能；研究了镍酸镧缓冲层对薄膜样品性能的影响。添加镍酸镧缓冲层增加了样品的漏电流,铁电性能也有很大区别,最后首次研究了这个系列薄膜的磁性能,并对这一系列性能进行了详细的分析。更多还原

【Abstract】 Recently, because of the special mechanical, thermal, electrical, optical and other properties or the coupling function between the mechanical, electrical, acoustic, optical, thermal, magnetic, functional ceramics are widely used in the the electric energy storage, energy conversion, the large displacement actuators and other fields. In the past decade, the increasingly strong awareness of environmental protection make the lead-free functional ceramics gaining more and more attention. Barium zirconate titanate and modified by doping has been recognized because of its excellent electrical performance and mature preparation process, such as (Ba1-xCax)(Zr1-y,Tiy)03(BCZT) and its doping. We use the traditional solid phase method to prepare (Ba0.85Ca0.15)(Zr0.10Ti0.90)O3-xmol%of Mn (0≤x≤0.5) ceramic and we use sol-gel method (Ba0.90Ca0.10)(Zr0.25Ti0.75)O3thin films and studied their electrical properties.Relaxation characteristics was shown the dielectric temperature characteristics of the samples sintered1200℃measured at different frequencies. According to the formula of Maxwell Wagner theory and Vogel-Fulcher (VF) relationship, we obtain the value of activation energy Ea=1.15eV. The maximal dielectric constant (ε) of the BCZT ceramics increases rapidly with the increase of sintering temperature and reaches the maximum value of9530at1300℃, then decrease with further increase of sintering temperature. We take charge the permittivity by Curie-Weiss (modified) Law. All the BCZT ceramic sintered in different times shows good ferroelectric properties, and their remanent polarization Pr and coercive field Ec show regularity change with different sintering temperature, respectively. The piezoelectric constant d33increase with increasing the sintering temperature as well, from the value of81.1at1200℃to a maximum value of291pC/N respectively, at1270℃.In order to understand the impact on the performance of Manganese dioxide doped the the pure BCZT ceramics,(Ba0.85Ca0.15)(Zr0.10Ti0.90) O3-x mol%MnO2was (x=0.1,0.2,0.3,0.4,0.5) ceramics were prepared. The results shows that MnO2had a great influence on the dielectric properties of the BCZT ceramics. SEM is made on the ceramic samples with different content of Mn found that when x≈0.3, manganese ion doped in to the grains of BCZT ceramic and be saturation, for x>0.3manganese ions doped into the grain boundary. First of all, manganese doping reduce the dielectric constant of BCZT ceramic. According to the modified Curie-Weiss law, we get the diffuseness constant y of the BCZT-xMn mol%ceramic increases from1.80to1.94as the Mn content increases from0to0.5%. And then the pyroelectric was research, the pyroelectric coefficient was calculated.In addition, the phase, microstructure, dielectric and ferroelectric properties of thin films with and without LaNiO3buffer layer prepared by a sol-gel process. We studied the influence of the nickel-lanthanum (LaNiO3) buffer layer to thin films performance. The ferroelectric properties are also very different, and finally for the first time to study the magnetic properties of this series of films and detailed analysis had been done.更多还原