Tungsten-deuterium co-deposition: Experiment and analytical description

Deuterium to tungsten ratio in co-deposited films was measured in a wide range of deposition temperatures from room temperature to 800 K. The experimental curve had 3-4 steps of decrease, which cannot be described by empirical scaling known from literature. A simple analytical model based on 1-dimensional diffusion equation with trapping was developed. A good agreement of the model and the experiment was obtained suggesting three types of traps in W-D co-deposited layers with detrapping energies of 0.74 ± 0.08 eV, 1.18 ± 0.12 eV, and 1.56 ± 0.16 eV and atomic concentration of traps of 2.3%, 1.8%, and 1.0%, respectively.