Photocontrol of the Magnetic Response of Molecular Magnets at Interfaces

非技术摘要：类聚合物分子网络比普通固态材料更柔软。当分子磁体被化学连接到光活性分子网络上时，温度的变化和光的照射在界面附近的磁畴上产生应变。这一单一的研究人员奖允许在宏观晶体中没有的新的纳米级环境中研究这些过程。这些结果为探索自旋电子学中新的应用领域的光控、磁性器件提供了基础。这项研究是跨学科和国际化的，初级研究人员由本科生和研究生组成，在与不同的团队合作的同时，接受广泛的实验、理论和计算技能培训。斯洛伐克的一个国际团队密切参与了这些实验，这种富有成效的合作为每个人提供了科学和文化接触。有组织的外展活动以K-8学生和教师为重点，动手活动的目的是提高所有参与者的科学知识。技术摘要：分子基磁体的性能可以通过合成方案进行调整，并可以通过温度、电场/磁场、压力/应变和光照射等外部刺激进行控制。这项单一研究者研究的目标之一是研究配位聚合物的纳米异质结构的磁响应的光控制机制，其中一个磁性成分与一个光活性成分配对。自旋极化小角中子散射(SANS)技术非常适合于探测和测量这些异质结构纳米粒子两个组分之间的界面处和附近的磁场分布的变化。另一个目标是改变放置在纳米织构亚稳定形态中的自旋交叉络合物的光活性状态。通过将分子限制在纳米相环境中并调节底物的影响，纳米尺度结构域的协作性被修改为允许在更高的温度下进行光开关。扫描隧道光谱是这些表面研究的主要工具，实验结果与专注于新材料的硅胶设计的内部计算团队交互共享。这些结果直接影响到未来的研究，即定义适用于自旋电子应用的可光切换的纳米尺度分子排列。

Non-Technical Abstract:Polymer-like molecular networks are softer than common solid-state materials. When a molecular magnet is chemically attached to a photoactive molecular network, changes of temperature and irradiation by light generate strains on the magnetic domains near the interface. This single investigator award allows for the study of these processes in new, nano-scaled environments that are not available in macroscopic crystals. The results provide a basis for exploring light-controlled, magnetic devices for new applications in spintronics. The research is interdisciplinary and international in scope, and junior researchers, comprised of undergraduate and graduate students, are trained in a wide-range of experimental, theoretical, and computational skills while working with a diverse team. An international team in Slovakia is intimately involved in the experiments, and this productive collaboration provides scientific and cultural exposure for everyone. Organized outreach activities focus on K-8 students and teachers, and hands-on activities are designed to enhance the science content knowledge of all participants.Technical Abstract:The properties of molecule-based magnets can be tuned by synthesis protocols and controlled by external stimuli such as temperature, electric/magnetic fields, pressure/strain, and irradiation by light. One goal of this single investigator research is to investigate the mechanisms governing the photocontrol of the magnetic response of nano-sized heterostructures of coordination polymers, where one magnetic component is mated to a photo-active constituent. Spin-polarized small-angle neutron scattering (SANS) techniques are well-suited to detect and measure the changes of the magnetic profiles at and near the interface between the two components of these heterostructured nanoparticles. Another goal is to shift the photoactive states of spin-crossover complexes placed in nano-textured, metastable morphologies. By restricting the molecules to a nanophase environment and tuning the influence of the substrate, the cooperativity of the nano-scaled domains is modified to allow photo-switching at higher temperatures. Scanning tunneling spectroscopy is the main tool for these surface studies, and the experimental results are interactively shared with an in-house computational team that is focused on the in-silico design of new materials. The results directly impact future investigations to define photo-switchable nano-scaled molecular arrangements suitable for spintronic applications.