CAREER: Microstructure-Property Relationships in Carbon-Based Nanostructures

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This CAREER award supports theoretical research to elucidate the role of microstructure in determining the properties of interfacial materials and supports education activities that involve introducing various materials modeling components to the materials science and engineering curriculum, development of multimedia and visual teaching tools, and outreach to K-12 educational activities. Research will focus on mechanical properties of brittle interfacial materials through the study of diamond interfaces and nanocrystalline diamond model systems. Studies of mechanical properties of interfacial brittle materials will focus on analyzing the role of microstructure and environmental effects in brittle fracture with particular emphasis on relating atomistic simulations to the large body of knowledge on fracture mechanics. Its purely brittle nature and its potential for various applications such those needed for developing micro- and nano-electromechanical systems motivate the choice of nanocrystalline diamond, a model brittle material. The PI will use atomistic simulations to address the questions: (i) Is brittle crack propagation governed mainly by equilibrium thermodynamics or is it dominated by kinetics? (ii) What are the effects of microstructure on crack propagation, deflection and arrest? (iii) What are effects of temperature and environment on fracture? In order to explore a wide range of microstructures and provide a highly reliable description of carbon-hydrogen systems, atomistic simulations will be combined with tight-binding simulations. Simulation results will be compared with those from continuum finite element modeling approaches to the mechanics of interfacial materials. Educational activities will focus on developing courses on materials theory and modeling, and on restructuring lecture-based coursework into an interactive format at both the undergraduate and graduate levels. A key aspect of educational activities will be to expose students to the complementary nature of modeling and experiment by developing coursework in collaboration with experimentalists. A variety of multimedia tools and web resources will be integrated into teaching to assist in achieving this objective. Cross-university web-assisted teaching will be explored in order to broaden the repertoire of the engineering curriculum. Platform independent, open source and interactive software for visualization of molecular and other physical processes will also be developed. This courseware and educational software will ultimately be shared with the materials science community. The educational component also includes an outreach program to expose K-12 students to materials science and materials science career options.This CAREER award supports theoretical research and education. The proposed research focuses on using simulation to elucidate the role of the microsctructure of materials in determining their mechanical properties. A simulation approach that couples two different simulation methods that are accurate on different length scales will be used to provide an atomistic description of brittle fracture in brittle interfacial materials through the study of diamond interfaces and nanocrystalline diamond model systems. The educational component of the proposal involves introducing materials modeling and simulation into the materials science and engineering curriculum through course development and restructuring, and involves developing new simulation and visualization software tools for teaching which will be shared with the materials science community. The educational component also includes an outreach program to expose K-12 students to materials science and materials science career options.