The serial sectioning technique was used to study 54Mn diffusion in ultra-pure crystals (cation impurity content of less than 10-7) and pure crystals (several ppm of impurity but intrinsic). The diffusion of Mn2+ in intrinsic material was found to proceed via 2 distinct mechanisms. At temperatures ranging from 320 to 430C, the results could be described by:

D (cm2/s) = 2.9 exp[-1.20(eV)/kT]

At temperatures ranging from 76 to 320C, the results could be described by:

D (cm2/s) = 1.8 x 10-5 exp[-0.59(eV)/kT]

The results for the entire temperature range could be described by:

D (cm2/s) = 42 exp[-1.37(eV)/kT] + 1.3 x 10-5 exp[-0.58(eV)/kT]

The results (table 41) suggested that the process which predominated at high temperatures was the usual vacancy mechanism, while migration at lower temperatures was controlled mainly by a small concentration of highly mobile interstitial ions.

A.L.Laskar, L.M.Slifkin: Journal of Nonmetals, 1972, 1[1], 83-92

 

Table 40

Diffusion of Li+ in AgCl Single Crystals

 

Temperature (C)

D (cm2/s)

250

1 x 10-9

300

8.1 x 10-9

350

4.2 x 10-8

400

1.6 x 10-7

 

Table 41

Diffusivity of 54Mn in Doped AgCl

 

Dopant

Temperature (C)

D (cm2/s)

30ppmCd

200.5

6.78 x 10-12

30ppmCd

273.3

3.60 x 10-11

30ppmCd

320.5

2.03 x 10-10

30ppmCd

360.5

8.80 x 10-10

30ppmCd

398.0

2.31 x 10-9

40ppmMn

200.5

7.09 x 10-12

40ppmMn

252.5

2.72 x 10-11

40ppmMn

320.5

2.04 x 10-10

40ppmMn

353.6

6.26 x 10-10

40ppmMn

398.0

2.74 x 10-9

40ppmMn

450.5

9.11 x 10-9

100ppmMn

156.6

4.01 x 10-12

100ppmMn

199.4

1.36 x 10-11

100ppmMn

220.4

3.16 x 10-11

100ppmMn

320.5

2.01 x 10-10

2000ppmCd

238.7

2.69 x 10-10

2000ppmCd

265.1

5.76 x 10-10

2000ppmCd

322.8

1.63 x 10-9

2000ppmCd

365.5

3.96 x 10-9

10000ppmCd

200.5

3.20 x 10-10

10000ppmCd

258.5

9.41 x 10-10

10000ppmCd

351.2

4.76 x 10-9

10000ppmCd

450.5

1.34 x 10-8