The migration of small homovalent cations in the monocrystalline material was studied by using tracer/sectioning methods. It was found that the results (table 198) could be described by the expression:

D (cm2/s) = 74.4 exp[-34.94(kcal/mol)/RT]

The temperature dependence of the isotope effect for 22Na and 24Na (table 199) was described by:

E = 126 exp[-13.3(kcal/mol)/RT]

It was concluded that the diffusion behavior of the cations was in good agreement with the so-called displaced homovalent small-radius cation model.

Diffusion and Isotope Effects in the Diffusion of Homovalent Cations in Cesium Iodide. S.M.Klotsman, I.P.Polikarpova, G.N.Tatarinova, A.N.Timofeev: Physical Review B, 1988, 38[11], 7765-76

 

Table 195

Self-Diffusion of 131I in Single Crystals of CsI

 

Temperature (C)

Technique

D (cm2/s)

155.7

sectioning

1.05 x 10-13

198.5

sectioning

4.34 x 10-13

209.2

sectioning

2.78 x 10-13

259.9

sectioning

2.88 x 10-12

278.5

sectioning

1.18 x 10-11

405.5

sectioning

1.58 x 10-10

435.0

sectioning

3.47 x 10-10

447.4

sectioning

5.59 x 10-10

451.5

sectioning

7.73 x 10-10

471.7

sectioning

1.10 x 10-9

continued

 

Table 195 (continued)

Self-Diffusion of 131I in Single Crystals of CsI

 

Temperature (C)

Technique

D (cm2/s)

522.9

sectioning

3.50 x 10-9

562.7

sectioning

1.10 x 10-8

155.7

Gruzin

1.36 x 10-13

198.5

Gruzin

4.92 x 10-13

209.2

Gruzin

2.91 x 10-13

259.9

Gruzin

2.98 x 10-12

278.5

Gruzin

1.15 x 10-11

405.5

Gruzin

1.64 x 10-10

435.0

Gruzin

3.66 x 10-10

447.4

Gruzin

5.61 x 10-10

451.5

Gruzin

7.13 x 10-10

471.7

Gruzin

1.01 x 10-9

522.9

Gruzin

3.60 x 10-9

562.7

Gruzin

8.77 x 10-8