Diffusion of 7Be through polycrystalline unirradiated specimens of BeO was studied. The isotope was deposited on one end of cylindrical specimens by exchange and adsorption from aqueous solution. The depth of penetration perpendicular to the deposition surfaces was determined after annealing. A simple lapping method of high precision was used to determine the penetration depths. For polycrystalline cold-pressed and sintered material, the diffusion behaviour at 1150 to 1800C were described by:

D(cm2/s) = 2.49 x 10-3 exp[-62500/RT]

H.J.De Bruin, G.M.Watson: Journal of Nuclear Materials, 1964, 14, 239-47