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

非技术描述：硅基体系结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，特别是那些成分可以定制和优化的材料，带来了新的科学机会。自从十年前发现了石墨烯以来，世界各地都在寻找其他的2D层状结构。石墨烯是一层单一的2D碳原子，是十年前诺贝尔物理学奖的主题。这项研究的重点是一类新的2D层状材料，称为磷酸盐，其中磷、硫和类似元素以复杂的平面马赛克图案排列。这项研究开发和探索了金属磷酸盐作为一类新的陶瓷材料，因为它们具有独特的量子行为，具有磁性、铁电性和耦合性质。这种独特的非线性现象的结合为陶瓷科学的发展提供了丰富的机会，并为新一代磁电子器件创造了一个潜在的平台。这一新兴的研究领域可能会催生新的技术产业，并需要在新型多组分陶瓷材料及其表征方面拥有广泛实践专业知识的劳动力。因此，研究活动与教育和社会推广活动相结合，以2D层状陶瓷材料的独特平台为基础。其他更广泛的影响目标包括对本科生和研究生进行先进材料研究方面的培训，并将研究成果纳入课程和课程。通过一个创新的“材料-新闻”项目，麦迪尔学院新闻专业的学生将身临其境地见证科学过程，并在他们的新闻博客和报道中报告他们的发现。相反，研究团队成员学习讲故事的新闻实践，以及如何将复杂的科学事业综合成与公众有意义的话语。总体而言，这项研究促进了科学见解，展望了2D陶瓷新类别的技术突破，为研究生和本科生提供了教育机会，并通过新闻倡议扩大了社会影响。技术细节：本研究围绕2D层状金属磷酸盐(MCP)的合成和高级表征展开，即硫代磷酸盐和硒磷酸盐，这是一类新型的2D层状陶瓷系统。基于各种可能的化学组合，特别是与杂阴离子的组合，合成的结构很容易采用广泛的多峰表征方法来描绘它们的复杂结构特征以及它们的线性和非线性性质。特别令人感兴趣的是探索空间和维度约束的作用的单层和少层2D结构。这一目标是通过经典的机械剥离和实验室开发的基于蒸汽的沉积方法来实现的。此外，这个项目还调查了铁电和铁磁性质之间的耦合的性质和程度，特别是在少数层和单层中。主要集中在磁性M2P2Q6(M=Cr，Mn，Fe，Co，Ni，Q=S，Se)和铁电/铁磁AMP2Q6(A=Ag，Cu，M=In，Ga，Cr，Mn，Fe，Gd)。不同但集成的多模式技术和表征方法被用来揭开多个长度尺度上复杂的微观结构迷宫。先进的扫描和透射电子显微镜技术探测局部结构、物相、化学分配和相关现象。与实验工作密切相关的理论工作考察了材料的整体性质，并分析了硫代和硒磷酸盐异质结构中的介观和纳米现象及其与衬底的相互作用。由具有空间和维度约束的异阴离子体系的不寻常组合管理的科学见解预计将显示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NSF的法定使命，并通过使用基金会的智力优势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.