Student: Bennett Mandal
Committee: Dr. Christopher Muhich & Dr. Jay Oswald
Abstract:
Diffusion modeling of mixed metal oxide materials is investigated to create a computational method for determining anionic diffusivity. First principles Density Functional Theory (DFT) calculations are performed to determine surface transition activation energy barriers to oxygen diffusion. These results are combined with previous work determining bulk diffusion barriers to create a comprehensive Kinetic Monte Carlo surface-bulk diffusion simulation. Simulations of undoped and Zr, Pr, Gd doped ceria are conducted to determined oxygen vacancy concentration profiles as a function of time and distance from the surface. A simplified one-dimensional version of Fick’s Second Law is fit to the concentration profile to estimate the oxygen diffusivity of the material. Challenges encountered in developing the diffusion algorithm delayed progress but it was found that KMC diffusion modeling based on activation energy barriers produced a viable model for predicting surface-bulk diffusion patterns. Further research is required to determine viability of Fick’s Second Law fitting to estimate oxygen diffusivity.
Zoom Room: https://asu.zoom.us/j/4677825380
Presentation Time: 12:00-1:00 PM (Arizona Time)
