CAREER: Computational Modeling of Microstructure Evolution during Vapor Deposition

该学院早期职业发展奖的研究目标是通过结合使用原子模拟和相场模拟，阐明与气相沉积过程中微结构发展和演变相关的基本纳米和中尺度机制。在历史上，气相沉积过程中的微结构发展模型是通过广泛的实验和材料表征来建立的。这些唯象模型没有考虑原子或介观材料的行为，因此不能预测氧化铝等复杂的异相材料体系的微观结构发展。在这项工作中，将使用原子模拟来了解离子通量在相演变中的作用，并计算氧化铝中固体亚稳相间的界面能。这些信息将被合并到相场模型中，并用于研究在模拟物理气相沉积条件下氧化铝薄膜中的相形成和演变。物理气相沉积被选为本职业提案中感兴趣的应用，因为它与不同的科学和工程学科广泛相关。这项建议致力于建立气相沉积过程中微结构形成的预测模型；这样的模型将允许工业在模拟环境中改进工艺条件，而不是通过广泛的实验和材料表征。这项研究计划与旨在激励下一代青年男女追求科学、技术、工程和数学(STEM)的教育和推广活动相结合。建议与当地童子军组织建立伙伴关系，为童子军创造机会，在STEM相关领域获得荣誉徽章或项目奖章。

The research objective of this Faculty Early Career Development (CAREER) award is to elucidate the fundamental nanoscale and mesoscale mechanisms associated with microstructure development and evolution during vapor deposition, through combined use of atomistic and phase-field simulations. Historically, models for microstructure development during vapor deposition are formulated via extensive experimentation and materials characterization. These phenomenological models do not consider atomic or mesoscale material behavior and thus cannot predict microstructure development in complex heterophase material systems, such as alumina. In this work, atomistic simulations will be used to provide an understanding of the role of ion flux on phase evolution and to compute interface energies between solid metastable phases in alumina. This information will be incorporated into a phase-field model and used to study phase formation and evolution in alumina thin films during simulated physical vapor deposition conditions.Physical vapor deposition is selected as the application of interest in this CAREER proposal because of its broad relevance across a diverse range of science and engineering disciplines. This proposal strives for a predictive model of microstructure formation during vapor deposition; such a model will allow industry to refine process conditions in a simulation environment rather than through extensive experimentation and materials characterization. This research plan is integrated with education and outreach activities designed to inspire future generations of young men and women to pursue science, technology, engineering and math (STEM). A partnership is proposed with local Boy and Girl Scout organizations to create opportunities for Boy and Girl Scouts to earn merit badges or project award patches in STEM related fields.