Isolobal Solutions to the Hysteresis Challenge in Single-Molecule Magnetism

含有稀土元素的磁性材料是现代社会不可或缺的，其应用范围从风力涡轮机和电动汽车电池的大规模到智能手机和计算机硬盘驱动器（HDD）等小型设备。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的独特磁性来处理和存储数字信息。该技术正在努力跟上数据生成的速率以及通过日益复杂的计算机建模过程来处理数据的需求。为了满足现代社会的需求及其对生成极大量数据的渴望，迫切需要开发能够存储这些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，我们提出了一个简单的前提下开发解决方案的问题：尺寸问题。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允许单位面积存储更多的数字信息。传统的稀土磁性材料由尺寸在几十纳米尺度上的颗粒组成。在本项目中，我们将合成一系列被称为单分子磁体（SMMs）的稀土磁体，它们在单个分子水平上存储磁信息，通常尺寸小于1纳米。分子磁体相对于传统的原子磁体具有一个主要优势，即可以通过改变稀土元素所在的化学环境来合理地改善其性能。这一点使我们能够解决SMM研究中的主要挑战，即它们的特性只能在用冷冻剂冷却后才能观察到，这是昂贵且不切实际的。在一项突破性的开发中，PI报告了第一个在液氮沸点以上显示磁记忆效应的SMM。该基准系统的更广泛意义在于，它为开发新一代高温SMM提供了蓝图。因此，在本项目中，我们将开发创新的化学路线，以获得新一代SMM，其特性可以在前所未有的高温下观察到。该项目的成功可能会朝着将这些材料纳入功能性器械的方向迈出重要一步。

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.