Exploring Growth Mechanisms of Nonequilibrium Nanostructured Materials

探索非平衡纳米结构材料的生长机制

• 批准号: 1609625
• 负责人: ZhiFeng Huang
• 金额: $ 20万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-15 至 2020-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609625&HistoricalAwards=false
• 关键词: Exploring; Growth; Mechanisms; Nonequilibrium; Nanostructured

NONTECHNICAL SUMMARYThis project supports theoretical and computational research on the study of novel materials growth mechanisms and the integration with education and outreach activities. An important phenomenon during the materials growth or fabrication process is the formation and evolution of structures at the nanoscale, which plays a pivotal role in controlling material properties that are of fundamental and technological importance. This research addresses a fundamental challenge of understanding and predicting the growth and self-assembly of nanostructured materials, particularly how to effectively tackle the complexity of the systems which are far from the tranquil state of equilibrium and require a description that can span a wide range of length scales and include interconnected processes across length scales. The PI will develop predictive modeling methods and conduct theoretical analyses and computer simulations to investigate the growth and dynamics of novel nanostructures that emerge from these processes, and predict new types of modulated structures in thin films under various material growth or processing conditions.This project supports the training and education of graduate students, and involves the PI's broader education efforts for the research community through lecture development for summer schools and workshops. This project incorporates the PI's outreach activities for STEM education in an all-girls minority public school in Detroit. The activities include the instruction and support of high-school student science projects and the training of Wayne State education undergraduates, to enhance the K-12 STEM education for young women who are underrepresented minority students and the professional development of both pre-service and in-service science teachers.TECHNICAL SUMMARYThis project supports theoretical and computational research integrated with education to provide a systematic study on the growth and dynamics of nonequilibrium nanostructured materials. The research addresses a fundamental challenge of understanding and predicting the growth mechanisms underlying the nanostructure assembly in functional material systems, particularly for systems that are out of equilibrium and governed by effects of coupling among different spatial scales that control material microstructures and dynamics. This research focuses on the exploration of novel nanostructures that are both morphologically and compositionally modulated, through three parts of investigation: (i) the development of modeling approaches based on the phase field crystal method and amplitude formalism, which can bridge mesoscopic and microscopic scales and incorporate system elasticity and plasticity, (ii) the study of nanostructure formation and dynamics during material heteroepitaxy, particularly for strained quantum dots modulated by nanoscale compositional patterns or eutectic microstructures, and (iii) the investigation of coupling mechanisms at meso and micro scales, for the coupling between morphological and compositional meso-scale instabilities and the coupling between meso and micro scales determining different growth modes. Comprehensive studies will be conducted numerically and analytically to identify various material growth mechanisms and the growth conditions for achieving controllable and coherent nanostructures, and predict new types of modulated structures in heteroepitaxial systems. The overall objective of this research is to advance our understanding of both structural and compositional dynamics in nonequilibrium and nanostructured material systems. This project also integrates the efforts of graduate and undergraduate education, and outreach activities designed for pre-service and in-service science teachers and their high-school students' science projects, to enhance K-12 science education for young women in Detroit who are underrepresented minority students.

非技术性总结本项目支持关于新材料生长机制研究的理论和计算研究，并与教育和推广活动相结合。在材料生长或制造过程中的一个重要现象是纳米结构的形成和演化，其在控制具有基础和技术重要性的材料性质方面起着关键作用。这项研究解决了理解和预测纳米结构材料的生长和自组装的基本挑战，特别是如何有效地解决系统的复杂性，这些系统远离平衡的平静状态，需要一个可以跨越广泛长度尺度的描述，并包括跨长度尺度的相互关联的过程。PI将开发预测建模方法，并进行理论分析和计算机模拟，以研究从这些过程中出现的新型纳米结构的生长和动力学，并预测在各种材料生长或加工条件下薄膜中的新型调制结构。并通过暑期学校和研讨会的讲座开发，涉及PI对研究界更广泛的教育工作。该项目结合了PI在底特律一所全女生少数民族公立学校开展的STEM教育推广活动。这些活动包括指导和支持高中学生的科学项目和培训韦恩州教育本科生，加强K-12 STEM教育的年轻女性谁是代表性不足的少数民族学生和专业发展的职前和在职该项目支持与教育相结合的理论和计算研究，以提供关于教育的系统研究。非平衡纳米结构材料的生长和动力学。该研究解决了理解和预测功能材料系统中纳米结构组装的基本生长机制的根本挑战，特别是对于那些不平衡的系统，以及由控制材料微观结构和动力学的不同空间尺度之间的耦合效应所控制的系统。这项研究的重点是探索新的纳米结构，无论是形态和成分调制，通过三个部分的调查：（i）基于相场晶体方法和振幅形式主义的建模方法的发展，其可以桥接介观和微观尺度并结合系统弹性和塑性，（ii）材料异质外延期间纳米结构形成和动力学的研究，特别是对于由纳米级组成图案或共晶微结构调制的应变量子点，以及（iii）在中尺度和微尺度的耦合机制的研究，用于形态学和组成的中尺度不稳定性之间的耦合以及确定不同生长模式的中尺度和微尺度之间的耦合。全面的研究将进行数值和分析，以确定各种材料的生长机制和实现可控和连贯的纳米结构的生长条件，并预测在异质外延系统调制结构的新类型。这项研究的总体目标是推进我们的理解在非平衡和纳米结构材料系统的结构和成分动力学。该项目还整合了研究生和本科生教育的努力，以及为职前和在职科学教师及其高中学生的科学项目设计的外联活动，以加强底特律少数民族学生中代表性不足的年轻女性的K-12科学教育。