Dinuclear Metal Tetracarboxlates Molecule-based Magnets

技术总结：本项目的目标是通过建立结构-功能关系来阐明基础科学，以识别具有重要技术性能的新磁体，并利用我们已经发现的钌基磁体的异常磁性。目标性能包括：增强有序温度（Tc），可控矫顽力场（Hcr），以及扩展和开发其异常磁性能。[Ru2(O2CMe)4]3[Cr(CN)6]磁体（Tc = 33 K）具有2个互穿晶格，导致异常磁滞和零场冷却/场冷却磁化等现象。当施加压力时，其Tc可逆地增加79%至59 K，反常的蜂腰形迟滞在12.8 kbar时变为正常。确定起源和扩展和利用互穿晶格的磁性后果为这一家族的磁铁是有针对性的。第二晶格导致异常行为，这是由第二晶格引起的新现象的罕见例子。寻找具有更高Tc和压力可控矫顽力的新实例。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。通过制备和研究[M2(O2CMe)4]3[Cr(CN)6] （M = Rh, Mo）来验证控制自旋耦合符号(J)观察铁磁非铁磁耦合的有效性。这项工作得到了美国国家科学基金会材料研究部固态与材料化学项目的支持。非技术总结：磁性在科学和技术上极其重要，因为它是每年200亿美元产业的基础。有机基磁体能够开发新的磁体家族，具有以前未观察到的特性组合，并提供对磁性的更深入和更广泛的理解，为下一代材料和设备奠定更坚实的基础。通过结构控制来控制磁性行为，特别是对互穿结构的控制，将导致未来混合多功能材料的新性能和增强性能的发展。开发和利用新材料是下一代器件的关键，对于培养材料化学许多跨学科方面的本科生、研究生和博士后学者至关重要，重点是新型磁铁的设计、合成、化学和磁性表征。这项研究工作有助于开展外联活动，如面向K-12学生和社区观众的听众参与讲座，以及让少数民族高中生和本科生参与研究活动，并协助记者报道技术主题。新磁性材料的研究是一项全球性的事业，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态与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.