Unconventional Heteroanion Ceramics: 2D Layered Seleno- and Thio-Phosphates

非技术描述：硅基架构的性能现在正接近物理控制的基本极限。因此，随着过去几十年传统硅微电子技术的飞速发展，迫切需要新的材料和新的结构。在这种背景下，新兴的二维（2D）材料带来了新的科学机遇，特别是那些成分可以定制和优化的材料。自从10年前获得诺贝尔物理学奖的单层碳原子石墨烯被发现以来，世界各地都在研究其他二维层状结构。这项研究的重点是一类新的二维层状材料，称为磷磷酸盐，其中磷，硫和类似元素排列在一个复杂的平面马赛克图案。本研究开发和探索了金属铜磷酸盐作为一类新的陶瓷材料，其磁性，铁电性和耦合性，具有不同寻常的量子行为。这种独特的非线性现象组合为推进陶瓷科学提供了丰富的机会，并为新一代磁电子器件创造了潜在的平台。这个新兴的研究领域可能会产生新的技术产业，并需要在新型多组分陶瓷材料及其表征方面具有广泛实践经验的劳动力。因此，研究活动与教育和社会推广活动相结合，以独特的二维层状陶瓷材料平台为基础。其他更广泛的影响目标包括在先进材料研究方面培养本科生和研究生，并将研究成果纳入课程和课程。通过创新的“材料-新闻”项目，梅迪尔学院的新闻学生沉浸在科学过程中，并在他们的新闻博客和报道中报道他们的发现。相反，研究团队成员学习新闻实践的故事讲述，以及如何将复杂的科学事业综合成有意义的话语与公众。总的来说，这项研究推进了科学见解，为新型二维陶瓷的技术突破提供了前景，为研究生和本科生提供了教育机会，并通过新闻倡议进行了社会推广。技术细节：本研究围绕二维层状金属铜磷酸盐（MCP）的合成和高级表征，即硫代磷酸盐和硒代磷酸盐，作为一种新型的二维层状陶瓷体系。锚定在各种可能的化学组合上，特别是与杂阴离子，合成的结构很容易适用于广泛的多模态表征方法，以映射其复杂的结构特征，结合其线性和非线性性质。特别感兴趣的是单层和少数层状二维结构，以探索空间和维度约束的作用。这一目标是通过经典的机械剥离以及在实验室开发的气相沉积方法来实现的。此外，本项目还研究了铁电和铁磁特性之间耦合的性质和程度，特别是在多层和单层中。主要重点是磁性的M2P2Q6 （M= Cr,Mn,Fe, Co, Ni， Q=S, Se）和铁电/铁磁性的AMP2Q6 （A=Ag,Cu， M=In,Ga,Cr,Mn,Fe,Gd）。采用多种多样但集成的多模态技术和表征方法来揭示跨多个长度尺度的复杂微观结构迷宫。先进的扫描和透射电子显微镜技术探测局部结构，相，化学分配和相关现象。理论工作与实验工作密切相关，研究了材料的体积特性，分析了硫代磷酸盐和硒代磷酸盐异质结构中的介观和纳米尺度现象及其与底物的相互作用。由空间和维度约束的异质离子系统的不寻常组合所支配的科学见解有望显示出不寻常的线性和非线性铁电和铁磁以及耦合性质和现象。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 DESCRIPTION: The performance of silicon-based architecture is now approaching fundamental limits governed by physics. Thus, there is a critical need for new materials and novel structures that may follow the meteoritic growth of conventional silicon microelectronic technology of the past few decades. In this context, new scientific opportunities are presented by emerging two-dimensional (2D) materials, especially those whose composition can be tailored and optimized. Ever since the discovery of graphene, a single 2D layer of carbon atoms, which was the subject of Physics Nobel prize a decade ago, other 2D layered structures are being pursued worldwide. This research focuses on a new class of 2D layered materials, called chalcophosphates where phosphorous, sulphur and analogous elements are arranged in an intricate planar mosaic pattern. This research develops and explores metal chalcophosphates as a new class of ceramic materials for their magnetic, ferroelectric, and coupled properties, with unusual quantum behavior. This unique combination of non-linear phenomena provide rich opportunities to advance science of ceramics, and creates a potential platform for new generation of magneto-electronic devices. This emerging research field is likely to generate new technology industries and require workforce with extensive hands-on expertise in novel multicomponent ceramic materials and their characterization. As a result, research activities are integrated with educational and societal outreach initiatives, anchored by the unique platform for 2D layered ceramic materials. The other broader impact goals include training of undergraduate and graduate students in advanced materials research and incorporation of research results into course and curricula. Through an innovative "Materials-Journalism" program, Medill school journalism students immerse to witness the scientific process and report their findings in their journalism blogs and reports. Conversely, the research team members learn journalism practices of story-telling and how to synthesize complex scientific undertaking into meaningful discourse with the public. Collectively, the research advances scientific insights with prospects for technology breakthroughs in the new class of 2D ceramics, with educational opportunities for graduate and undergraduate students, and societal outreach through the journalism initiative. TECHNICAL DETAILS: This research revolves around synthesis and advanced characterization of 2D layered metal chalcophosphates (MCP), i.e. thiophosphates and selenophosphates, as a new and novel class of 2D layered ceramic systems. Anchored on a variety of possible chemical combinations, especially with heteroanions, the synthesized structures are readily amenable to extensive multimodal characterization methods to map their complex structural characteristics in conjunction with their linear and non-linear properties. Of specific interest are single- and few layered 2D structures to explore the role of spatial and dimensional constraints. This goal is accomplished by classical mechanical exfoliation as well as vapor-based deposition methods developed in the laboratory. Also, this project investigates the nature and extent of coupling between ferroelectric and ferromagnetic properties, especially in the few- and single layers. The primarily focus is on magnetic M2P2Q6 (M= Cr, Mn, Fe, Co, Ni, Q=S, Se) and ferroelectric/ferromagnetic AMP2Q6 (A=Ag,Cu, M=In,Ga,Cr,Mn,Fe,Gd). A diverse yet integrated multimodal techniques and characterization methods are employed to unravel the complex labyrinth of microstructure across multiple length-scales. Advanced scanning and transmission electron microscopy techniques probe the local structure, phases, chemical partitioning, and related phenomena. Theoretical work conducted in close connection with the experimental efforts examines the bulk properties of materials and analyzes the meso and nano-scale phenomena in heterostrucure architectures of thio- and selenophosphates and its interaction with substrates. The scientific insights governed by unusual combination of heteroanion systems with spatial and dimensional constraints are expected to display unusual linear and non-linear ferroelectric and ferromagnetic as well as coupled properties and phenomena.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.