Isolobal Solutions to the Hysteresis Challenge in Single-Molecule Magnetism

含有稀土元素的磁性材料对现代社会是不可或缺的，其应用范围从大型风力涡轮机和电动汽车电池到小型设备，如智能手机和计算机硬盘驱动器(HDD)。在硬盘驱动器中使用稀土特别重要，因为传统的数据处理技术依赖于这些元素独特的磁性来处理和存储数字信息。这项技术正在努力跟上数据产生的速度和通过日益复杂的计算机建模过程处理数据的需求。为了满足现代社会的需求及其产生极大数据量的渴望，迫切需要开发能够存储该数据同时减小存储介质的物理尺寸的新型磁性材料。在这个项目中，我们建议基于一个简单的前提来开发解决方案：大小很重要。硬盘中可以存储的数据量取决于磁性颗粒的大小；使这些颗粒更小应该可以在单位面积上存储更多的数字信息。传统的稀土磁性材料由几十纳米尺度的颗粒组成。在这个项目中，我们将合成一系列被称为单分子磁体(SMM)的稀土磁体，它在单个分子的水平上存储磁信息，通常尺寸小于1纳米。与传统的原子磁体相比，分子磁体具有一个重大优势，即可以通过改变稀土元素所处的化学环境来合理地改善它们的性能。这方面使我们能够解决SMM研究中的主要挑战，即只有在用冷冻剂冷却时才能观察到它们的特性，这是昂贵和不切实际的。PI报告了第一个在液氮沸点以上显示磁记忆效应的SMM，这是一个突破性的发展。这一基准体系更广泛的意义在于，它为发展新一代高温SMM提供了蓝图。因此，在这个项目中，我们将开发新一代SMM的创新化学路线，其性能可以在前所未有的高温下观察到。该项目的成功将潜在地向将这些材料纳入功能装置迈出重要的一步。

Magnetic materials containing rare-earth elements are indispensable to modern society, with their myriad applications ranging from the bulk scales of wind turbines and batteries for electronic vehicles to small-scale devices such as smart phones and computer hard-disk drives (HDDs). The use of rare earths in HDDs is particularly important since conventional technology for data processing relies on the unique magnetic properties of these elements to process and store digital information. This technology is struggling to keep pace with the rate at which data is generated and with the demands for processing it through increasingly sophisticated computer modelling processes.To meet the demands of modern society and its thirst for generating extremely large amounts of data, there is a pressing need to develop new types of magnetic material capable of storing this data whilst simultaneously decreasing the physical size of the storage medium. In this project, we propose to develop solutions to the problem based on a simple premise: size matters.The amount of data that can be stored in an HDD depends on the size of the magnetic particles; making these particles smaller should allow more digital information to be stored per unit area. Conventional rare-earth magnetic materials consist of particles with dimensions on the scale of tens of nanometres. In this project, we will synthesize a family of rare-earth magnets known as single-molecule magnets (SMMs), which store magnetic information at the level of individual molecules, typically with dimensions of less than one nanometre.Molecules offer a major advantage over conventional atom-based magnets, which is that their properties can be improved rationally by changing the chemical environment in which the rare-earth elements reside. This facet allows us to address the major challenge in studies of SMMs, which is that their properties can only be observed upon cooling with cryogens, which is expensive and impractical.In a ground-breaking development, the PI reported the first SMM to show magnetic memory effects above the boiling point of liquid nitrogen. The wider significance of this benchmark system is that it provides a blueprint for developing a new generation of high-temperature SMM. Therefore, in this project we will develop innovative chemical routes to a new generation of SMM with properties that can be observed at unprecedentedly high temperatures. Success with this project will potentially take an important step towards the incorporation of these materials into functional devices.