A Crossover of Molecular and Extended Magnetism in Engineered Solids

工程固体中分子和扩展磁性的交叉

• 批准号: 2003783
• 负责人: Kirill Kovnir
• 金额: $ 48.92万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003783&HistoricalAwards=false
• 关键词: Crossover; Molecular; Extended; Magnetism; Engineered

Part I: Non-technical SummaryMagnetic materials have shaped our modern society because they are crucial for advances in the fields of renewable energy, electric engines, sensors, and data storage. There are two types of magnetic materials - molecular magnets, composed of isolated molecules, and extended solid or itinerant magnets with infinite frameworks of chemical bonds within the crystal structure. Molecular magnets are appealing due to their synthesis at low temperatures and high tunability but suffer from weak magnetic interactions. In turn, extended solid magnets exhibit strong magnetic interactions and large magnetic moments in the ordered state but have limited tunability. The current project is focused on bridging the gap between molecular and extended solid magnets by synthesizing a unique set of hybrid compounds, which combine advantages of both classes of magnetic materials. In the proposed hybrid compounds, tunable molecular fragments will be sandwiched in between one- and two-dimensional fragments of extended solid magnets. Understanding how structure determines properties is the key step for design of emerging materials. Thus, to achieve significant breakthroughs in the magnetic materials development, we are establishing fundamental relationships between structure and nature of interactions of molecular and extended fragments, and magnetic properties of the produced materials. In the educational component of the project, chemistry graduate and undergraduate students are engaged in chemistry demonstrations at local elementary schools, the Iowa State STEM Program for Women in Science and Engineering, and the Des Moines Science Center to foster interest of K-12 students and adults in chemistry. This project is supported by the Solid State and Materials Chemistry Program in the Division of Materials Research.Part II: Technical SummaryExploration of chemical factors that affect magnetic interactions in solids is one of the major steps in the development of novel magnetic materials. Current solid state syntheses lack the predictability and rationality of organometallic and coordination chemistry. To achieve high predictability and rationally design magnetic materials, hybrid magnetic materials comprising infinite Fe-chalcogenide fragments separated by interstitial coordination metal complexes are being developed. In this way, strong magnetic interactions and tunability are segregated into two different sublattices of a hybrid material. The project uses coordination chemistry methodology to tune molecular transition metal amine complexes which are incorporated in between or connected to extended infinite Fe-chalcogenide fragments of itinerant magnets. It is anticipated that chirality and spin-crossover properties of coordination complexes will be translated to the itinerant Fe-chalcogenide fragments. An advantage of the target hybrids is that strong magnetic interactions and large magnetic moments present in the Fe-chalcogenide sublattice will either amplify the weak magnetic signatures of spin-crossover transitions or produce chiral magnets. In the educational component of the project, chemistry graduate and undergraduate students are engaged in chemistry demonstrations at local elementary schools, the Iowa State STEM Program for Women in Science and Engineering, and the Des Moines Science Center to foster interest of K-12 students and adults in chemistry. This project is supported by the Solid State and Materials Chemistry Program in the Division of Materials Research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第一部分：非技术摘要材料已经塑造了我们的现代社会，因为它们对于可再生能源，电动发动机，传感器和数据存储领域的进步至关重要。有两种类型的磁性材料 - 分子磁铁，由孤立的分子组成，并在晶体结构内具有无限的化学键框架扩展固体或巡回磁铁。分子磁体由于其在低温下的合成和高可调性而吸引人，但磁相互作用弱。反过来，延长的实心磁铁在有序状态下表现出强烈的磁相互作用和较大的磁矩，但可调性有限。当前项目的重点是通过合成一组独特的混合化合物来弥合分子和扩展固体磁体之间的差距，这些化合物结合了两类磁性材料的优势。在提出的杂化化合物中，可调分子片段将夹在延伸固体磁体的一维片段之间。了解结构如何确定属性是设计新兴材料的关键步骤。因此，为了在磁性材料的发展中取得重大突破，我们正在建立分子和扩展片段相互作用的结构与性质之间的基本关系，以及生产材料的磁性。 在该项目的教育部分中，化学研究生和本科生在当地小学，爱荷华州科学和工程领域的女性STEM计划以及得梅因科学中心从事化学示范，以促进K-12学生和成人化学的兴趣。 该项目得到了材料研究部的固态和材料化学计划的支持。第二部分：影响固体中磁相互作用的化学因子的技术摘要是新型磁性材料开发的主要步骤之一。当前的固态合成缺乏有机金属和协调化学的可预测性和合理性。为了实现高可预测性和合理设计磁性材料，正在开发包含无限的Fe-Chalcogenide片段，这些材料由间质配位金属络合物分开。这样，强烈的磁相互作用和可调性被隔离为混合材料的两个不同的sublattices。该项目使用协调化学方法来调整分子过渡金属胺复合物，这些金属胺复合物在巡回磁体的延伸无限的无限无限型核苷片段中融合或连接。可以预料，配位配合物的手性和自旋交叉特性将转化为流动的Fe-Chalcogenide片段。目标杂种的一个优点是，在Fe-Chalcogenide sublattice中存在的强磁相互作用和大磁矩将放大自旋交叉过渡的弱磁特征，或产生手性磁铁。在该项目的教育部分中，化学研究生和本科生在当地小学，爱荷华州科学和工程领域的女性STEM计划以及得梅因科学中心从事化学示范，以促进K-12学生和成人化学的兴趣。 该项目得到了材料研究部的固态和材料化学计划的支持。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来支持。

项目成果

Modulation of transport properties via S/Br substitution: solvothermal synthesis, crystal structure, and transport properties of Bi 13 S 17 Br 3

通过 S/Br 取代调节传输特性：Bi 13 S 17 Br 3 的溶剂热合成、晶体结构和传输特性

• DOI: 10.1039/d2dt02295h
• 发表时间: 2022
• 期刊: Dalton Transactions
• 影响因子: 4
• 作者: Amarasinghe, Dinesh K.;Yox, Philip;Viswanathan, Gayatri;Adeyemi, Adedoyin N.;Kovnir, Kirill
• 通讯作者: Kovnir, Kirill

Non-innocent Intercalation of Diamines into Tetragonal FeS Superconductor

二胺非无害嵌入四方 FeS 超导体

• DOI: 10.1021/acsaem.0c02996
• 发表时间: 2021
• 期刊: ACS Applied Energy Materials
• 影响因子: 6.4
• 作者: Harmer, Colin P.;Pak, Chongin;Greenfield, Joshua T.;Adeyemi, Adedoyin N.;Gamage, Eranga H.;Kovnir, Kirill
• 通讯作者: Kovnir, Kirill

Pseudo-Polymorphism in Layered FeS Intercalates: A Competition between Charged and Neutral Guest Species

• DOI: 10.1021/acs.chemmater.2c00270
• 发表时间: 2022-06
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Colin P. Harmer;S. Kamali;O. Lebedev;Shannon J. Lee;R. Ribeiro;P. Canfield;K. Kovnir

Tuning of Cr–Cr Magnetic Exchange through Chalcogenide Linkers in Cr 2 Molecular Dimers

通过 Cr2 分子二聚体中的硫属化物连接基调节 Cr–Cr 磁交换

• DOI: 10.1021/acs.inorgchem.2c00298
• 发表时间: 2022
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Gamage, Eranga H.;Ribeiro, Raquel A.;Harmer, Colin P.;Canfield, Paul C.;Ozarowski, Andrew;Kovnir, Kirill
• 通讯作者: Kovnir, Kirill