International Conference on Advanced Ceramics and Composites: Time TBA
Location: Daytona Beach, Florida
In this presentation progress on the development of such an approach will be presented. The application of atomic scale model generation to amorphous hydrogenated boron carbide will be shown. The retention of molecular substructure and the formation of medium range order are key components of the process. Comparison of the resultant models with variance data from fluctuation electron microscopy analysis of comparable growth samples will be used to help judge the product quality.
Annual Materials Science & Technology (MS&T) Meeting: Time 3:40 pm
Location: Columbus, Ohio
This presentation will discuss an integrated program for the design of complex disordered solids. The program includes a general methodology for simulating the atomic structure of substructure-containing amorphous solids and mapping resultant structures/properties back to fabrication conditions with the ultimate goal of enabling a design capability. The program centers on ab-initio molecular dynamics and hybrid reverse Monte Carlo simulation algorithms, augmented by geometry constraints. They will be coupled with experimental input and feedback including (1) solid-state nuclear magnetic resonance techniques to obtain specific bonding and connectivity information; (2) the sensitive medium-range order information available from fluctuation electron microscopy—a specialized technique based on transmission electron microscopy—and (3) neutron diffraction. The thin-film amorphous preceramic polymer a-BC:H will be shown as a suitably complex and technologically relevant case study.
The project combines state of the art computational techniques (AIMD, HRMC), modern optimization algorithms (e.g. artificial neural networks (ANNs), particle swarm optimization (PSO)), specialized experimental characterization techniques, (solid-state nuclear magnetic resonance (NMR), 4-dimensional scanning transmission electron microscopy (4D-STEM)), and advanced thin-film fabrication technology (plasma enhanced chemical vapor deposition (PECVD)). We will use a collection of thin-film amorphous preceramic polymers (a-BC:H, a-SiBCN:H, and a-SiCO:H) as suitably complex and technologically relevant case studies.