Non-centrosymmetric Quantum Materials through Metal-amine Complexes

这个项目得到了材料研究部固态和材料化学项目的支持，首席研究员（PI） Efrain Rodriguez教授和他在马里兰大学的研究小组将开发由铁、钴和镍等元素组成的新型量子材料，这些材料夹在硫等其他元素的薄层之间。开发具有独特量子特性的新型电子材料的概念可以实现许多科学家长期追求的量子信息革命。这项工作的一个独特之处在于，金属硫化物层的结合调用了其他物理性质，如磁性，这对量子信息应用很有吸引力。然而，这些层并不是随机地堆叠在一起，而是插入分子来指导堆叠顺序。因此，原子水平上的化学控制允许这些分子“扭曲”或“弯曲”金属硫化物层，从而为量子技术产生有吸引力的特性。这种在原子尺度上的精确控制使得设计新型量子材料成为可能。这些研究活动还包括通过使用3D打印机向大学公园附近的当地社区推广教育。PI和他的学生从化学数据库中提取了近50种不同的分子和材料，并将它们转化为3D打印结构。他们的“分子工艺”模型是当地高中化学教室的教学工具。PI与附近兰利公园国际高中（IHSLP）的教师合作，这是一所为STEM中代表性不足的学生提供服务的学校。PI和马里兰大学的学生提议与IHSLP学生合作，使用他们当地的3D打印机，也使用大学校园的资源。其目的是向学生传授使技术成为可能的材料，并激励他们考虑STEM职业。该项目由材料研究部固态和材料化学项目支持，将研究如何形成两种或更多不同的成分来创建新型混合材料，从而为新兴现象开辟新的途径。在拟议的研究活动中，杂化材料由插入二维（2D）金属硫属化合物的金属胺配合物组成。金属胺分子单元具有手性，并作为结构导向剂形成打破反转对称的晶体结构。研究活动还探讨了金属胺配合物的- nh2基团与金属硫属化合物末端Q2-阴离子（Q = S和Se）之间的氢键对晶体结构的影响。为了产生非中心对称的量子材料，这种相互作用应该扭曲或弯曲二维层。非中心对称量子材料的晶体生长是在溶剂热条件下进行的。晶体生长的溶剂是胺双端配体L，形成[ML3]n+配合物，其中M = Mn, Fe, Co， Ni或Cu。托管MQ层被归类为四面体过渡金属硫族化合物（ttmc），与研究得很好的过渡金属二硫族化合物（如MoS2， WTe2）相反，它具有方形金属亚晶格，并容纳第一排较小的过渡金属。目标相包括具有非中心对称超导性的铁基和镍基ttmc，以及具有“铁电”流动磁性的Co和mn基ttmc。外展到当地的学校IHSLP，使用3D打印来教授学生无机分子和无机材料。学生将学习结构与性质之间的关系，以及在可充电电池、太阳能电池和超导体等技术中发挥重要作用的材料。3D打印分子工艺套件开始与价壳电子对排斥（VSEPR）理论，教学生结构的基础知识。IHSLP也有3D打印功能，PI有一个网页，其中所有的3D打印文件目前托管。代表性也很重要，因此另一个目标包括向学生展示科学领域更多样化的代表性。3D打印项目是一座桥梁，将他们与通往不同STEM职业道路的信息联系起来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical summaryWith this project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, principal investigator (PI) Prof. Efrain Rodriguez and his research group at the University of Maryland will develop new types of quantum materials consisting of elements such as iron, cobalt, and nickel that are sandwiched between thin layers of other elements such as sulfur. The concept of developing new types of electronic materials that possess unique quantum properties can enable the revolution in quantum information long sought after by many scientists. A unique aspect of the work is that the incorporation of metal sulfide layers invokes other physical properties such as magnetism that are enticing for quantum information applications. These layers, however, do not randomly stack on top of one another and instead molecules are inserted that guide the stacking sequence. Chemical control at the atomic level therefore allows these molecules to ‘twist’ or ‘bend’ the metal sulfide layers into producing attractive properties for quantum technologies. This precise control at the atomic scale allows the design of novel quantum materials. These research activities also include outreach to the local community around College Park in education through the use of 3D printers. The PI and his students have taken close to 50 different molecules and materials from chemical databases and turned them into 3D printed structures. Their model kits called MolecularCraft serve as instructional tools in the chemistry classroom in local high schools. The PI collaborates with the faculty at the nearby International High School at Langley Park (IHSLP), which is a school that serves students underrepresented in STEM. The PI and students from the University of Maryland propose to engage with IHSLP students using their local 3D printers but also resources on the university campus. The aim is to teach the students about materials that make technologies possible and to inspire them to consider STEM careers.Technical summaryThis project, supported by the Solid State and Materials Chemistry Program in the Division of Materials Research, will examine how two or more disparate components can be formed to create new types of hybrid materials which can open new avenues towards emergent phenomena. In the proposed research activities, hybrid materials consist of metal-amine complexes inserted into two-dimensional (2D) metal chalcogenides. The metal-amine molecular units are chiral and serve as structure directing agents to form crystal structures that break inversion symmetry. The research activities also investigate how much hydrogen bonding between the –NH2 groups of the metal amine complexes and the terminal Q2- anions (Q = S and Se) of the metal chalcogenides dictates crystal structure. To give rise to non-centrosymmetric quantum materials, such interactions should either twist or bend the 2D layers. The crystal growth of non-centrosymmetric quantum materials takes place under solvothermal conditions. The solvent for crystal growth is an amine bidendate ligand L that forms [ML3]n+ complexes, where M = Mn, Fe, Co, Ni, or Cu. The hosting MQ layers are classified as tetrahedral transition metal chalcogenides (TTMCs), which in contrast to the well-studied transition metal dichalcogenides (e.g. MoS2, WTe2), have a square metal sublattice and accommodate smaller transition metals of the first row. The targeted phases include Fe- and Ni-based TTMCs for non-centrosymmetric superconductivity and Co- and Mn-based TTMCs for ‘ferroelectric’ itinerant magnetism. Outreach to the local school, IHSLP, uses 3D printing to teach students about inorganic molecules and inorganic materials. Students learn about structure-property relationships and about materials that play important roles in technology such as rechargeable batteries, solar cells, and superconductors. The 3D printing MolecularCraft kits start with Valence Shell Electron Pair Repulsion (VSEPR) theory, to teach students the basics of structure. IHSLP also has 3D printing capabilities, and the PI has a webpage where all the 3D printing files are currently hosted. Representation matters too, so another goal includes demonstrating to the students a more diverse representation in the sciences. The 3D printing project serves as a bridge to connect them with information on the pathways to different STEM careers.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.