Abstract Scope |
Advanced manufacturing has been shown to be an alternative method for the development of sensors for in-pile nuclear reactor applications. Mo and Nb printed on alumina substrates are candidates for the construction of thermocouples that can monitor temperature due to their balance of temperature and irradiation resistance. However, the surface diffusion mechanisms of Mo and Nb adatoms on alumina, which play a critical role in the printing process, have not been fully addressed. We performed density functional theory-based calculations to study the adsorption and surface diffusion of Mo and Nb adatoms on the α-Al2O3(0001) surface. Nb adatoms have stronger adatom-surface interactions, and both Mo and Nb prefer to occupy the same adsorption sites. Nudged elastic band methods were used to calculate surface diffusion paths. Mo has a smaller diffusion energy barrier than Nb, resulting in a larger diffusion coefficient. Mo and Nb follow similar diffusion paths, potentially leading to site-blocking. |