The diffusion of protons and deuterons in a single crystal was studied by means of infra-red absorption. The chemical diffusion coefficient of protons was deduced from the relaxation time of the absorption intensity upon replacing deuterons with protons. The temperature dependence of the chemical diffusion coefficient of protons was described by:

D(cm2/s) = 0.16 exp[-210kJ/mol)/RT]

Y.Okuyama, N.Kurita, N.Fukatsu: Ionics, 2009, 15[1], 43-8