The low-temperature diffusivity of Ne in crystals of 2 types was investigated by monitoring desorption from crystals which had been previously saturated in the gas phase. One crystal type was cubic in shape and was obtained by the evaporation of aqueous solutions. The other crystals were obtained in the form of plates which were cleaved from a crystal that had been grown by using the Kyropoulos method. The results for the cubic crystals, at temperatures ranging from 100 to 400C, could be described by:

D (cm2/s) = 4.4 x 10-5 exp[-12.4(kcal/mol)/RT]

while those for the plate crystals, at temperatures ranging from 100 to 400C, could be described by:

D (cm2/s) = 2 x 10-7 exp[-0.8(kcal/mol)/RT]

A.Y.Kupryazhkin, P.V.Volobuev, P.E.Suetin: Zhurnal Fizicheskoi Khimii, 1975, 49[2], 546-7