铅铋基钙钛矿铁电薄膜的制备与电学性能研究

发布时间：2018-04-13 13:43

本文选题：钛酸铅 + 铁酸铋　；参考：《北京科技大学》2017年博士论文

【摘要】：铁电薄膜作为一类重要的多功能基础材料而倍受关注,在电子器件、信息技术、储能装置中有广泛的应用前景。钛酸铅和铁酸铋都是集铁电和压电等多种优异性能于一身的典型钙钛矿型材料,通过化学替代和应力工程的调控等途径可以有效对薄膜的结构和性能进行改良。本文以钛酸铅和铁酸铋为出发点,通过A位、B位不同元素替代和各向同性应力、基底双轴应力引入,采用不同的化学法和物理法制备出了一系列性能优异的铁电薄膜。系统的研究了化学替代和应力调控对钛酸铅基和铁酸铋基铁电薄膜的晶体结构、电子结构、晶格动力学、铁电性、铁磁性及铁电相关等性能的影响。首先研究不同元素取代对PbTiO3-BiMeO3体系的合成以及铁电等性能的影响。通过对PbTiO3-Bi(Zn1/2Zr1/2)O3, PbTiO3-Bi(Mg1/2Zr1/2)O3,PbTiO3-Bi(Mg1/2Ti1/2)O3三大薄膜体系的探索,不仅得到铁电性好、耐疲劳、温度稳定性好的铁电薄膜材料,还直接从实验的角度揭示Ti、Zn离子在PbTiO3-BiMeO3体系中的铁电活性分别大于Zr、Mg离子。同时在铁电体中首次通过高分辨X射线同步辐射直观揭示铁电极化复苏归因于畴结构的变化。通过“相界面”应力的引入,制备了大轴比的超四方PbTiO3复合外延薄膜。报道了目前铁电体中的最大剩余极化(236.3μC/cm2)。同时相转变温度从块体的490℃提高到了725℃。第一性原理计算、透射电镜、X射线吸收谱等手段观察和解释了“相界面”应力的作用和巨大极化的原因。第一次采用脉冲激光法(PLD)在A1203基底上成功制备了大轴比BiFe03的外延薄膜。通过变温同步辐射的测试,得到了薄膜的低膨胀特性。通过第一性原理计算、变温磁性等表征解释了低膨胀性的机理是铁电性、磁相转变、基底应力共同耦合的作用。采用Co和Ni对BiFe03基薄膜的取代,得到优异铁电性、巨大铁电阻变、可翻转的铁电光伏的多功能铁电薄膜。同时通过界面的调控,实现了铁电光伏信号三倍多的提高。
[Abstract]:Ferroelectric thin films have attracted much attention as a kind of multifunctional important basic material and information technology in the electronic device, the storage device has a wide application prospect. Lead titanate and bismuth ferrite are typical Perovskite Ferroelectric and piezoelectric materials in a variety of excellent performance in a body, and alternative stress engineering control approaches can effectively on the structure and properties of thin films were modified by chemical. The lead titanate and bismuth ferrite as the starting point, through A, B different element substitution and isotropic stress, basal biaxial stress introduced by different chemical method and physical method to prepare a series of performance excellent ferroelectric thin films was studied. The chemical substitution and stress control of crystal structure of lead titanate and bismuth based ferroelectric thin film electronic structure, lattice dynamics, ferroelectric, ferromagnetic and ferroelectric effect related properties. First of all. The different elements substitution effect on the PbTiO3-BiMeO3 system of the synthesis and properties of ferroelectric. Based on PbTiO3-Bi (Zn1/2Zr1/2) O3, PbTiO3-Bi (Mg1/2Zr1/2) O3, PbTiO3-Bi (Mg1/2Ti1/2) to explore the O3 three thin film system, not only have good ferroelectric properties of ferroelectric thin film materials, fatigue resistance, good temperature stability, but also reveal directly from Ti the angle of the experiment, the activity of Zn ferroelectric ions in PbTiO3-BiMeO3 system were greater than Zr, Mg ion. At the same time for the first time in ferroelectrics by high resolution synchrotron radiation X ray directly reveal the ferroelectric polarization recovery is attributed to the domain structure changes. According to the introduction of "interface" stress, super tetragonal PbTiO3 composite epitaxial thin shaft the ratio was prepared. The ferroelectric in maximum residual polarization reports (236.3 C/cm2). At the same time, the phase transition temperature increased from block 490 C to 725 C. First principle calculation, transmission electron microscope, X ray The absorption spectrum is used to observe and explain the reason of the effect of interfacial stress and great polarization. First by pulsed laser method (PLD) was successfully prepared large axial ratio of BiFe03 epitaxial thin films on A1203 substrates. The temperature dependent synchrotron radiation test, obtained the low expansion properties of thin films by. The first principle calculation, and explains the low temperature magnetic characterization of the expansion mechanism is ferroelectric, magnetic phase transition, the substrate stress coupling effect. The Co and Ni of BiFe03 films obtained excellent substitution, ferroelectricity, huge iron resistance, multifunctional ferroelectric thin film ferroelectric photovoltaic flip. At the same time through the interface control, realizes signal ferroelectric photovoltaic three times more improved.

【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB383.2

【参考文献】