多场耦合环境下磁力/电力显微镜原位测量原理的研究

The objectives of modern magnetic materials and devices can be summarized by the slogan“smaller, functional and energy-saving”. These applications lead to an urgent requirement to locally observe and precisely control the magnetic or electric domains under the combination of magnetic field, electric field, as well as the alternating field. Magnetic or electric force microscopy (MFM or EFM)is a powerful tool to investigate the magnetic or electric domains in nanometer length scales, however, In-situ observing the magnetic or electric domains under the coupling of muiti-fields, with adjustable frequency, high sensitivity, and ultra-high resolution, has not yet been performed, although these pose serve problems for materials design and analysis. In this project, based on the side-band frequency modulation of the cantilever, we will plan to investigate the theories for In-situ observe the magnetic or electric domains under the combination of muiti-fields, such as magnetic field, electric field, as well as the alternating field. To develop this method, we will clarify the new concepts for the side-band frequency modulations, MFM/EFM quantifications and reconstructions; By using this equipment, we will In-situ observe the nanocale magnetic or electric domains, and control the domain motions by electric field, with ultra-high resolution (better than 5 nm); Based on the experimental measurement and theoretic analysis, we will explain the dynamics of magnetic or electric domains, as well as the mechanisms of ferromagnetic/ferroelectric coupling. This project sheds light on the development of magnetic topology structure, magnetic information storage, multiferroic, as well as the biomedicine materials.

磁性材料与器件向微型化、功能化、低能耗化的发展趋势，迫切需要研究集电场、磁场、交变场和原位表征于一体的电磁结构测量技术。磁力/电力显微镜是当前研究纳米材料中磁畴/电畴结构的重要方法之一。商用磁力/电力显微镜无法满足在多场耦合条件下进行原位测量，实现频率可调、高灵敏度和高空间分辨的要求。我们拟研究基于边带-频率调制的多场耦合磁力/电力显微镜精密测量原理，开展关于探针频率调制机理、磁力/电力图像定量化以及重构的新原理新方法研究；解决纳米结构中磁畴、电畴结构以及原位电场调控下磁畴运动的超高分辨率探测的关键技术（分辨率优于5nm）问题；阐明在多场耦合环境下超精细磁畴、电畴结构的相关动力学行为以及电磁耦合原位调控等关键科学问题。该研究课题有助于解决新型纳米材料在磁拓扑、磁信息存储、多铁性材料、生物医学材料等领域的基础科学问题。

磁力显微镜从发明之日起就成为研究纳米磁畴结构和磁场分布的强有力工具。现阶段磁力显微镜成像发展的一个方向就是整合不同的技术、方法、模块，研究在多场条件下进行原位电磁耦合调控和超高分辨率成像的方法，最终兼顾超高分辨率成像的优势，实现磁畴、电畴结构调控、以及电磁耦合信息的提取、互融和互参。本项目研究基于频率调制的多场耦合磁力/电力显微镜精密测量原理，开展具有在多场（包括电场，磁场，交变场）条件下进行磁畴、电畴结构信息表征及原位调控的新原理新方法研究，服务于信息存储、纳米磁性材料、铁电/铁磁体系等基础研究领域。该项目课题的意义一方面是发展多场耦合磁力/电力显微镜系统，阐明纳米材料的超精细磁畴、电畴结构及其原位调控机制，克服磁力/电力成像、多场耦合、超高分辨率探测等关键技术问题；另一方面是研究磁畴、电畴量化分析方法，量化解释纳米材料结构中精细磁畴的运动变化规律，解决新型纳米材料在磁拓扑、磁信息存储、多铁性耦合、生物医学等领域的基础科学问题。基于多场耦合磁力显微镜系统，课题组成功构筑了具有低能耗和高传输效率的一维磁涡旋链和二维磁涡旋网络，该研究成果将在磁功能器件、自旋波、自旋电子学等多个领域中产生积极广泛的影响，为电子器件向微型化和低功耗化发展提供关键技术支撑。