Controlled tuning of atomic structure in functional materials by acoustic waves and electric fields

通过声波和电场控制功能材料中原子结构的调谐

• 批准号: 409743569
• 负责人: Dr. Matthias Zschornak
• 金额: --
• 依托单位: Hochschule für Technik und Wirtschaft Dresden (HTW)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/409743569?language=en
• 关键词: Controlled; tuning; atomic; structure; functional

Active research in the field of condensed matter and nanotechnology not only led to significant progress in understanding the mechanisms of formation of electrical polarization and magnetoelectric phenomena, but also showed the possibilities of creating new classes of devices based on a combination of magnetoelectric and piezoelectric properties. Meanwhile, macroscopic properties, such as multiferroism and piezoelectricity, are associated with local structural changes that occur under the influence of external perturbations. The key ability to control such displacements requires careful study of their connection with the parameters of external fields, and is a fundamental task. Since structural changes at the atomic level caused by external influences are very small, methods for determining atomic displacements with high accuracy are required. New possibilities for that emerged recently due to the novel method developed by the German co-authors of this project (C. Richter et al., Nature Communications 2018), which allows to determine atomic displacements with picometer accuracy using resonant diffraction of synchrotron radiation. In this project, it is proposed to study the transformations in the structural characteristics of a number of piezoelectrics and multiferroics excited by standing acoustic waves and electric fields. For this it is proposed to develop a new method based on the appearance of forbidden Bragg reflections using Resonant X-ray Diffraction of synchrotron radiation and their amplification due to interference effects.It is expected that the results will give a better insight into the mechanisms, controlling the atomic displacement in functional materials under influence of external physical fields, as exemplified by a number of materials, such as such as LiNbO3/LiTaO3, Li2B4O7, Fe2Mo3O8, GaN, ZnO, RbH2PO4, BiFeO3, BaTiO3, and the MFP phase in SrTiO3, and quantitative information regarding the dependence of local atomic displacements on the amplitude and frequency of acoustic waves. Further, new methods for controlled and reversible transformation of structural parameters in functional materials and new experimental equipment compatible both with conventional X-ray sources as well as with the state of the art beamlines at synchrotron radiation facilities will be made available. The obtained results can significantly widen the range of functional materials and can be directly used in modern technological applications.

在凝聚态物质和纳米技术领域的积极研究不仅导致在理解电极化和磁电现象的形成机制方面取得了重大进展，而且还显示了在磁电和压电特性相结合的基础上创建新类别设备的可能性。同时，宏观性质，如多铁性和压电性，与局部结构的变化，发生外部扰动的影响下。控制这种位移的关键能力需要仔细研究它们与外场参数的关系，这是一项基本任务。由于外部影响引起的原子水平的结构变化非常小，因此需要高精度的原子位移测定方法。由于该项目的德国合著者开发的新方法，最近出现了新的可能性（C。Richter等人，Nature Communications 2018），它允许使用同步辐射的共振衍射以皮米精度确定原子位移。在这个项目中，它被提议研究在结构特性的一些压电和多铁性激发驻波声波和电场的转换。基于同步辐射的共振X射线衍射（Resonant X-ray Diffraction，RXD）的禁戒布拉格反射现象及其干涉效应的放大，提出了一种新的研究方法，以期更好地揭示功能材料中原子位移的控制机制，并以多种材料为例，例如LiNbO 3/LiTaO 3、Li 2B 4 O 7、Fe 2 Mo 3 O 8、GaN、ZnO、RbH 2 PO 4、BiFeO 3、BaTiO 3和SrTiO 3中的MFP相，以及关于局部原子位移对声波的振幅和频率的依赖性的定量信息。此外，还将提供对功能材料的结构参数进行可控和可逆变换的新方法，以及与传统X射线源和同步辐射设施的最新光束线兼容的新实验设备。所获得的结果可以显着拓宽功能材料的范围，并可直接用于现代技术应用。