Gas transport through materials can take place by two mechanisms;
diffusive flow via solubility-diffusion or flow through
defects in the material such as pinholes. Oxygen permeation
through high barrier coatings is dominated by flow through defects
in the coating (Chatham,1996). The principal mechanism of oxygen
transport through SiOx coated-barrier occurs through nano-scale
defects in the SiOx coating (Erlat & Spontak, 1999; Gruniger & Rohr,
2004).