Nickel self-diffusion in single-crystals was measured as a function of temperature and O2 pressure at 1182 to 1762C and from 1 to 5 x 10-7atm. In pure O2 and in pure CO2 the results could be expressed by:

pure O2:     D(cm2/s) = 4.8 x 10-2 exp[-60.8(kcal/mol)/RT]

pure CO2:     D(cm2/s) = 2.1 x 10-2 exp[-62.7( kcal/mol)/RT]

M.L.Volpe, J.Reddy: The Journal of Chemical Physics, 1970, 53[3], 1276-9