Ordering to two dimensional strained films

该奖项支持致力于研究金属表面超薄涂层或薄膜的理论研究和教育，重点是具有特殊蜂窝晶体对称性的新材料。例子包括石墨烯和六方氮化硼。这些薄膜已被证明具有不同寻常的电子和机械性能，许多研究人员正在努力开发技术应用。该奖项旨在表彰在不同实验条件下预测此类薄膜生长和性能的新理论方法的发展。该奖项支持在复杂的数学和计算技术方面培训研究生，并通过暑期学校、辅导和研讨会支持PI更广泛的教育活动。该项目涉及与欧洲、南美和非洲的研究人员的国际合作。该奖项支持材料物理学的理论研究和教育，具体应用于金属基板上二维或准二维薄膜的生长。薄膜和衬底之间的耦合产生了应变诱导的图像化和有趣的相称/不相称相变。这种系统的建模由于涉及许多可能的长度尺度而变得复杂，因为图案的尺寸在弱粘附极限下与薄膜/衬底错配应变成反比，并且在相称/不相称过渡附近可能会发散。为了克服这一困难，PI计划开发一种基于相场晶体模型的模型，该模型可用于研究微米级系统，并包含薄膜/衬底相互作用，弹性和位错的原子细节。PI将检查三角形和蜂窝基板上的蜂窝单层的顺序。这项工作的结果将适用于石墨烯、六方氮化硼和二硫化钼等材料体系。本研究的目的是预测作为失配应变、粘附强度和外部条件（如温度）的函数而形成的图案的性质。该奖项支持在复杂的数学和计算技术方面培训研究生，并通过暑期学校、辅导和研讨会支持PI更广泛的教育活动。该项目涉及与欧洲、南美和非洲的研究人员的国际合作。

NONTECHNICAL SUMMARYThis award supports theoretical research and education devoted to the study of ultra-thin coatings or films on metallic surfaces with emphasis on novel materials with a particular honeycomb crystalline symmetry. Examples include graphene and hexagonal boron nitride. These films have been shown to possess unusual electronic and mechanical properties that many researchers are working toward exploiting for technological applications. The award addresses the development of new theoretical methods for predicting the growth and properties of such films under different experimental conditions. This award supports training graduate students in sophisticated mathematical and computational techniques and the PI's broader educational activities through summer schools, tutorials, and workshops. This project involves international collaborations with researchers in Europe, South America, and Africa. TECHNICAL SUMMARYThis award supports theoretical research and education in materials physics with specific applications to the growth of two-dimensional or quasi two-dimensional films on metallic substrates. The coupling between the film and substrate gives rise to strain induced patterning and interesting commensurate/incommensurate phase transitions. Modeling such systems is complicated by the many possible length scales involved as the size of the patterns is inversely proportional to the film/substrate misfit strain in the weak adhesion limit and can diverge near the commensurate/incommensurate transition. To overcome this difficultly the PI plans to develop a model based on the phase field crystal model that can be used to study micron sized systems and incorporates atomistic details of the film/substrate interaction, elasticity and dislocations. The PI will examine the ordering of honeycomb monolayers on triangular and honeycomb substrates. The results of this work will be applicable to materials systems such as graphene, hexagonal boron nitride and molybdenum disulphide. The goal of this research is to predict the nature of the patterns that form as a function of misfit strain, adhesion strength and external conditions such as temperature. This award supports training graduate students in sophisticated mathematical and computational techniques and the PI's broader educational activities through summer schools, tutorials, and workshops. This project involves international collaborations with researchers in Europe, South America, and Africa.