Previous data on the diffusion of 22Na in single crystals were compared with new results on polycrystalline specimens (table 255). This indicated that the diffusion coefficients deduced for polycrystalline and monocrystalline samples were identical. It was concluded that Na did not diffuse via the grain-boundaries.

S.M.Klotsman, I.P.Polikarpova, A.N.Timofeev: Fizika Tverdogo Tela, 1970, 12[11], 3364-6

 

 

Table 255

Tracer Diffusion of 22Na in CsI

 

Sample

Temperature (C)

D (cm2/s)

polycrystalline

397.8

3.250 x 10-10

monocrystalline

397.8

3.205 x 10-10

polycrystalline

359.6

6.809 x 10-11

monocrystalline

359.6

6.611 x 10-11