Spectroscopy of molecule-based materials in high magnetic fields

高磁场中分子材料的光谱学

• 批准号: 1063880
• 负责人: Janice Musfeldt
• 金额: $ 41.7万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1063880&HistoricalAwards=false
• 关键词: Spectroscopy; molecule; based; materials; magnetic

TECHNICAL SUMMARY:The research outlined in this proposal, supported by the Solid State and Materials Chemistry Program, focuses on the optical and magneto-optical properties of molecule-based materials with the overarching goal of understanding the consequences of physical and chemical tuning on functionality. Building on key advances in the previous award period, this program concentrates on (i) magnetoelastic coupling in chemically simple molecular magnets, (ii) photophysical properties of quantum spin ladders and organic biradicals, and (iii) the interplay between charge, structure, and magnetism in these systems. Within these broad scientific areas, several model compounds that may show large or widely applicable magneto-optical effects have been identified. Examples include a series of chemically-related transition metal and mixed-metal cyanide systems like Mn(dca)2 and Cr(Ru2)3 with magnetic ordering and quantum critical transitions through which local lattice distortions can be analyzed. Also included are spin ladders like Cu(qnx)Cl2 and organic biradicals such as 1,4-diphenylenenitrene, where the color properties can be tuned with magnetic field. These materials offer additional complexity in their behavior compared to the S = 1/2 copper halide coordination polymers where novel high field effects were originally discovered yet they are well-controlled enough to act as model systems to meaningfully explore the phenomenology of quantum magnetism. What brings these efforts together is a common focus on coupling and functionality deriving from the interplay between charge, structure, and magnetism and the high field spectroscopic techniques that we use to investigate these phenomena. Findings from this comprehensive experimental program will further complementary research on magnetic oxides as well as theoretical development and device applications.NON-TECHNICAL SUMMARY:The overall goal of this program is to investigate the behavior of materials under extreme conditions, specifically those of very high magnetic fields. Two criteria are required to meet this objective. First, the target materials must have low energy scales, commensurate with experimentally realizable magnetic fields. Second, they must be soft enough to respond to an applied field. Molecular materials meet these benchmarks. While dynamical measurements reveal the interplay between charge, structure, and magnetism and provide broad insight into functionalities that depend upon such coupling, they also impart understanding of similar processes in higher energy scale materials like oxides where experimentally available magnetic fields are often insufficient to drive the most interesting transitions, some of which may be useful for magneto-optical devices. This program leverages the Joint Institute of Advanced Materials at the University of Tennessee and Oak Ridge National Laboratory, the facilities at the National High Magnetic Field Laboratory in Tallahassee and Los Alamos, and numerous connections with researchers at other academic institutions and national laboratories. At the same time, it supports the interdisciplinary education and training of a diverse group of young people for future employment in academics, government laboratories, and industry in the area of advanced materials. A broad range of educational, outreach, and service activities will also take place under the auspices of this National Science Foundation funded program, especially in the area of conference and workshop organization.

技术摘要：在固态和材料化学计划的支持下，该提案中概述的研究重点介绍了基于分子材料的光学和磁光学特性，其总体目标是了解物理和化学调谐功能对功能的后果。在上一项奖励期间，该程序的基础是（i）化学简单的分子磁体中的磁弹性耦合，（ii）量子自旋梯子和有机Biradicals的光物理特性，以及（iii）这些系统中电荷，结构和磁性之间的相互作用。在这些广泛的科学领域中，已经确定了几种可能显示出很大或广泛适用的磁光效应的模型化合物。示例包括一系列与MN（DCA）2和CR（RU2）3的化学相关过渡金属和混合金属系统，并具有磁性顺序和量子临界过渡，可以通过这些过渡分析局部晶格失真。还包括Cu（QNX）CL2和有机Biradical的自旋梯子，例如1,4-二苯基烯基烯烯，其中颜色性能可以用磁场调节。与S = 1/2铜卤化协调聚合物相比，这些材料的行为具有额外的复杂性，这些聚合物最初发现了新型的高场效应，但它们的控制良好足以充当模型系统，可以有意义地探索量子磁化的现象学。将这些努力融合在一起的是，人们普遍着重于我们用来研究这些现象的电荷，结构和磁性以及高场光谱技术之间的相互作用以及高场光谱技术。这个全面的实验计划的发现将进一步互补的磁氧化物以及理论开发和设备应用。Non-technical摘要：该计划的总体目标是研究极端条件下材料的行为，特别是磁场非常高。满足这一目标需要两个标准。首先，目标材料必须具有低能尺度，并与实验可实现的磁场相称。其次，它们必须足够柔软才能响应应用领域。分子材料符合这些基准。虽然动态测量揭示了电荷，结构和磁性之间的相互作用，并为依赖于这种耦合的功能提供了广泛的见解，但它们还对较高能量尺度材料（如氧化物）（例如实验可用的磁场通常不足以驱动最有趣的过渡）的氧化材料（例如，其中一些可能可用于磁场 - 光电器设备有用），它们也具有对相似过程的理解。该计划利用田纳西大学和橡树岭国家实验室，塔拉哈西国家高磁场实验室的设施和洛斯·阿拉莫斯的设施利用了高级材料联合研究所，以及与其他学术机构和国家实验室的研究人员的许多联系。同时，它支持一群年轻人的跨学科教育和培训，以在高级材料领域的学术，政府实验室和行业中的未来就业。在该国家科学基金会资助的计划的主持下，尤其是在会议和研讨会组织的领域，也将进行广泛的教育，外展和服务活动。