Study of Structure-Physical Properties Relation of New Materials with Reduced Dimensionality

本计画致力于借由压力调整维度来研究维度对一类新材料物理性质的影响。目标是达成一种理解，为特殊应用提供定制材料的基础。该项目是材料合成、高压技术应用和理论建模的结合。除了使用传统的金刚石砧座细胞和大容量的压力细胞的静水压力的研究，一个新开发的设备，同时应用静水压力和单轴应力将采用。这将允许以以前不可能的方式控制诸如晶格常数、键长和相互作用强度等参数。 这些实验方法与理论模型相结合，将有助于更好地理解结构-物理性能关系。其结果将是通过用化学压力（原子替代）代替我们测量的外部压力或通过在不晶格匹配的衬底上生长薄膜来改进材料的应用定制。将特别注意：1）合成具有基础和技术重要性的新材料，并研究其在环境压力和高压下的物理和化学性质; 2）使用一种新的装置来应用“纯”应变，这将允许在低温和磁场中进行传输和光学测量; 3）与洛斯阿拉莫斯国家实验室的工作人员开展理论建模方面的合作; 4）为研究生提供跨学科的教育机会。 该项目是材料研究和教育的实验和理论计划。实验研究将在科罗拉多州立大学进行，而理论工作将与洛斯阿拉莫斯国家实验室的工作人员合作完成。 化学家和物理学家在扩展他们控制更小和更复杂的电子器件的能力时所面临的科学问题将通过对低维材料的仔细研究来阐明，这些材料将专门为此目的而合成。 这些材料，显示约束的尺寸，可以表现为有效的，新的半导体线或原子尺寸或纳米器件片。 为了理解与低维材料相关的物理现象，将进行非常受控的研究，研究小组将沿着材料中预定的方向沿着仔细施加压力，以便将环境和尺寸变化与电子响应相关联。 通过理解低维材料中的基本物理现象，可以设计出新的，也许更有效的材料，这将改善传统的商业电子材料。该计划的一个重要特点是组装的多学科，国际研究团队。 研究将由学生谁将在学术，国家和国际实验室的化学家和物理学家团队的一部分进行。 学生将参与新材料的合成，表征和设计，并将前往洛斯阿拉莫斯和阿贡国家实验室的国家研究设施，利用最新的，最先进的仪器，并将与全国最好的化学家和物理学家互动。***

This project is devoted to investigating the influence of dimensionality on the physical properties of a new class of materials by tuning the dimensionality with pressure. The goal is to achieve an understanding which will provide the basis for tailoring materials for special applications . The project is a combination of materials synthesis, the application of high pressure techniques and theoretical modeling . In addition to the use of conventional diamond anvil cells and large volume pressure cells for hydrostatic pressure studies, a newly developed device for the simultaneous application of hydrostatic pressure and uniaxial stress will be employed. These will permit the control of parameters like lattice constant, bond length, and interaction strength in a manner not possible before. These experimental methods combined with theoretical modeling will lead to a better understanding of the structure - physical properties relation. The result will be improved tailoring of materials for applications by replacing the external pressure of our measurement by chemical pressure (substitution of atoms) or by growing thin films on substrates which are not lattice matched. Specific attention will be devoted to: 1)The synthesis of new materials of fundamental and technological importance and the investigation of their physics and chemistry at ambient and high pressure; 2) employ a new device for the application of "pure" strain which will allow transport and optical measurements at low temperatures and in a magnetic field; 3) develop collaborations concerning theoretical modeling with staff of the Los Alamos National Laboratory; and 4) provide interdisciplinary educational opportunities for graduate students.%%% This project is an experimental and theoretical program in materials research and education. The experimental studies will be conducted at the Colorado State University while the theoretical work will be done in collaboration with staff of the Los Alamos National Laboratory. The scientific problems that confront chemists and physicists in expanding their abilities to control smaller and more complex electronics will be elucidated through careful studies of low-dimensional materials which will be especially synthesized for this purpose. These materials, which display constrained dimensions, may behave as efficient, new semiconductor wires or sheets of atomic dimensions or nanodevices. In order to understand the physical phenomena associated with low-dimensional materials, very controlled studies will be performed whereby the research team will carefully apply pressures along predetermined directions in materials in order to correlate environmental and dimensional changes with electronic responses. By understanding the fundamental physical phenomena in low-dimensional materials, new, perhaps more efficient materials can be designed that will improve upon the conventional, commercial electronic materials. An important feature of the program is the multidisciplinary, international research team that is assembled. Research will be performed by students who will be part of a team of chemists and physicists in academic, National, and international laboratories. Students will participate in the synthesis, characterization and design of new materials and will travel to National research facilities at the Los Alamos and Argonne National Laboratories to utilize the latest, state-of-the-art instrumentation and will interact with the Nation's best chemists and physicists. ***