Dinuclear Metal Tetracarboxlates Molecule-based Magnets

技术概述：本项目的目标是通过建立结构-功能关系来确定具有重要技术性能的新磁体，并利用我们已经发现的Ru基磁体的异常磁性来阐明基础科学。目标性质包括：增强的有序温度(TC)、可控的矫顽场(Hcr)，以及扩展和开发它们的反常磁性。[Ru_2(O_2CMe)_4]_3[Cr(CN)_6]磁体(T_c=33K)有两个互穿晶格，导致反常磁滞和零场冷/场冷磁化强度等，其T_c随外加压力可逆增加79%至59K，在12.8kbar时，异常黄蜂腰形磁滞变正常。目标是确定互穿晶格的起源，并扩展和利用这一系列磁体的磁学后果。第二个晶格导致反常行为，这是第二个晶格产生的新现象的罕见例子。将发现具有更高的T_c和可由压力控制的矫顽力的新的例子。寻找由[FeII/III2(O2CR)4]+(S=9/2)，[Ru2(O2CR)4]n(n=0，2+)，[Ru(CN)6]3-，[OS2(O2CR)4]+和[M(NCS)6]3-组成的磁体。此外，通过制备和研究[M2(O_2CMe)_4]_3[Cr(CN)_6](M=Rh，Mo)来验证对自旋耦合符号(J)的控制以观察铁磁而不是亚铁磁性耦合。这项工作得到了NSF.NON材料研究部固态和材料化学计划的支持-技术摘要：磁性在科学和技术上极其重要，因为它是一个每年200亿美元的产业的基础。有机基磁体使新的磁体家族得以发展，具有以前没有观察到的性能组合，并提供了对磁性的更深层次和更广泛的理解，为下一代材料和器件奠定了更坚实的基础。通过结构控制来控制磁性行为，特别是对互穿结构的控制，将导致未来杂化多功能材料的新的和增强的性能的发展。开发和开发新材料是下一代器件的关键，对于本科生、研究生和博士后学者在材料化学的许多跨学科方面的培训至关重要，重点是新类别磁体的设计、合成、化学和磁性表征。这项研究努力致力于外展活动，如面向K-12学生和社区听众的听众参与的讲座，以及让少数族裔高中和本科生参与研究活动，并协助记者进行技术主题的报道。新型磁性材料的研究是一项世界性的事业，现有的与英国、西班牙、俄罗斯、韩国、日本和希腊科学家的全球合作将得到加强和扩大。这项工作得到了美国国家科学基金会材料研究部固体和材料化学项目的支持。

TECHNICAL SUMMARY: Elucidation of the fundamental science by establishing structure-function relationships to identify new magnets with technologically important properties and exploiting the anomalous magnetic properties we already discovered for ruthenium-based magnets is goal of this project. The targeted properties include: including enhanced ordering temperatures (Tc), controllable coercive fields (Hcr), and to extend and exploit their anomalous magnetic properties. The [Ru2(O2CMe)4]3[Cr(CN)6] magnet (Tc = 33 K) has 2 interpenetrating lattices that lead to anomalous hysteresis and zero-field cooled/field cooled magnetization etc. Its Tc reversibly increases by 79% to 59 K with applied pressure, and the anomalous wasp-waist shaped hysteresis becomes normal at 12.8 kbar. Identifying the genesis and extending and exploiting the magnetic consequences of the interpenetrating lattice for this family of magnets are targeted. The 2nd lattice leads to anomalous behaviors, and it is a rare example of new phenomena arising from a 2nd lattice. New examples with higher Tc and coercivity controllable by pressure will be identified. Magnets composed of [FeII/III2(O2CR)4]+ (S = 9/2), [Ru2(O2CR)4]n (n = 0, 2+), [Ru(CN)6]3-, [Os2(O2CR)4]+, and [M(NCS)6]3- composition are sought. Also, control of the sign of spin coupling (J) to observe ferromagnetic not ferrimagnetic coupling will be validated by making and studying [M2(O2CMe)4]3[Cr(CN)6] (M = Rh, Mo). This work is supported by the Solid State and Materials Chemistry program in the Division of Materials Research at the NSF.NON-TECHNICAL SUMMARY:Magnetism is scientifically and technologically exceedingly important as it is the basis of a $20-billion/yr industry. Organic-based magnets enable the development of new families of magnets with combinations of properties not previously observed as well as providing a deeper and broader understanding of magnetism to form a stronger foundation for next-generation materials and devices. Control of magnetic behavior via structure control, especially for interpenetrating structures, will lead to the development of new and enhanced properties for future hybrid multifunctional materials. Developing and exploiting new materials is key to next generation devices, and is essential for the training of undergraduate students, graduate students, and post-doctoral scholars in many interdisciplinary aspects of materials chemistry with emphasis on the design, synthesis, chemical, and magnetic characterization of a new class of magnets. This research endeavor lends itself to outreach activities such as talks with audience participation to K-12 students and community audiences, as well as having minority high school and undergraduate students participate in research activities and assist journalists with their reports on technical topics. The study of new magnetic materials is a worldwide enterprise, and existing worldwide collaborations with scientists in the UK, Spain, Russia, Korea, Japan, and Greece will be strengthened and expanded. This work is supported by the Solid State and Materials Chemistry program in the Division of Materials Research at the NSF.