A DFT Investigation of the Interactions of Pd, Ag, Sn and Cs with silicon carbide

With a view to understanding the diffusion of radionuclides through the silicon carbide layers in Tristructural Isotropic (TRISO) coated fuel particles, density functional theory (DFT) calculations are applied to palladium, silver, tin and caesium with silicon carbide. The silicon carbide molecule (Si2C2), crystalline cubic silicon carbide (β-SiC) and the (120) Σ5 grain boundary of β-SiC are investigated to elucidate the differences in the interactions of silicon carbide with these elements. The calculations show that the electronic interactions have a significant effect on the way these elements interact with the silicon and carbon atoms of silicon carbide. The lowest energy structure of the AgSi2C2 complex is unique to silver, although for all these elements low energy structures are formed where the metal atom lies to one side of a C-Si bond. By comparing the incorporation energies in the solid phases, it is possible to group these elements by similarities in the patterns of incorporation energies. Silver and palladium form a group with carbon, tin is grouped with silicon and caesium is on its own.

RABONE Jeremy;  KOVACS Attila; 

2014-12-09

WILEY-BLACKWELL

JRC89491

0020-7608,   

http://onlinelibrary.wiley.com/doi/10.1002/qua.24720/abstract,    jsessionid=00B2CA8BE656574ECE6E9FACAA72D9D6.f02t04,    https://publications.jrc.ec.europa.eu/repository/handle/JRC89491,   

10.1002/qua.24720,