Thin-layer deposition and sectioning techniques were used to investigate the isotope effect for the self-diffusion of 131Cs and 137Cs at temperatures ranging from 470 to 600C. The isotope effect was found to be independent of temperature (table 247). This indicated that the contribution of divacancies to self-diffusion was small, and that the predominant mechanism of self-diffusion involved free monovacancies.

S.M.Klotsman, I.P.Polikarpova, G.N.Tatarinova, A.N.Timofeev: Physica Status Solidi B, 1974, 63[1], 153-62

 

 

Table 247

Diffusivity of 131Cs and 137Cs in CsI Single Crystals

 

Temperature (C)

D (cm2/s)

E

604

3.14 x 10-8

0.507

599

2.72 x 10-8

0.523

588

1.91 x 10-8

0.560

534

4.40 x 10-9

0.532

503

1.65 x 10-9

0.532

499

1.79 x 10-9

0.554

471

5.96 x 10-10

0.551