|About this Abstract
||MS&T22: Materials Science & Technology
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||Plateau-Rayleigh Instability with a Grain Boundary Twist
||Omar Marwan Hussein, Keith Coffman, Khalid Hattar, Eric Lang, Shen Dillon, Fadi Abdeljawad
|On-Site Speaker (Planned)
||Omar Marwan Hussein
Recent advances in high-precision manufacturing techniques have enabled the fabrication of materials architectures with intricate nanoscale features. However, the microstructural stability of nanoscale rod morphologies remains poorly understood. Our recent experiments demonstrate a morphological instability in which a polycrystalline micro- or nanoscale rod breaks up into single-crystal domains, a phenomenon reminiscent of the Plateau-Rayleigh instability. Here, we develop a theoretical model to investigate the impact of grain boundaries (GBs) on the morphological instabilities of polycrystalline nanoscale rods. A neutral stability surface is obtained, which demarcates stable and unstable perturbations with respect to the breakup. We complement our thermodynamic treatment with phase-field simulation studies that capture the kinetics of morphological instability. The theoretical and phase-field modeling studies are in agreement with our experimental studies on a model Alumina system. In broad terms, our present work provides a framework to study the microstructural stability of nanoscale ligament geometries.