Kinetic Theory of Hydrogen Uptake for Getter Materials

In the paper the kinetics of hydrogen absorption was studied, and a basic model was presented for the non-evaporable getter material. It is believed that hydrogen uptake process of getters should be composed of three intermediate partial steps: dissociative chemisorption on the surface, surface penetration to the bulk, and diffusion in the body. The potential barrier at the surface for adsorbed hydrogen atoms transporting to the bulk (subsurface layer) can not be neglected. Under the normal conditions, these processes must be considered and their kinetic equations should be solved simultaneously. For low hydrogen bulk concentration a lattice-gas model was adopted to describe the diffusion behavior of hydrogen in the bulk. Influence of some factors on hydrogen (absorption) rate was also discussed.