Electron microprobe analysis was used to determine interdiffusion coefficients for monocrystalline solid solutions which contained up to 75ppm of total cation impurities (table 187). It was found that the compositional dependence of the coefficients passed through a maximum that shifted to higher CaF2 concentrations at higher temperatures. Extrapolation of the interdiffusion coefficients to the extremes of composition furnished impurity diffusion coefficients that agreed well with tracer results.

R.Scheidecker, M.F.Berard: Journal of the American Ceramic Society, 1973, 56[4], 204-6

 

 

Table 187

Arrhenius Parameters for Interdiffusion

in the CaF2-SrF2 System at 1100 to 1320C

 

CaF2 (mol%)

Do (cm2/s)

Q (kcal/mol)

0

1.91 x 103

89.6

10

1.45 x 103

88.4

20

1.39 x 103

87.6

30

3.26 x 103

89.7

40

1.77 x 104

94.4

50

6.37 x 104

97.8

60

1.81 x 105

100.6

70

3.65 x 105

102.4

80

2.70 x 105

101.5

90

1.23 x 105

99.0

100

2.88 x 105

102.1