The conductivity was determined as a function of composition and temperature (table 15). The maximum value of 3 x 10-4S/cm, at 25C, was found for a 2-phase material which contained 20mol%AgBr. The substitution of Br- into AgI or of I- into AgBr solid solutions led to anomalously large increases in the conductivity. These increases could not be explained in terms of charge compensation, and were instead attributed to purely elastic displacements which arose from the differing sizes of the substituted ions. A quadratic dependence of the conductivity upon the content of substituted ions was found. As an example of the anomaly, a mixture which contained 30mol%AgI exhibited a conductivity of 7S/cm at 380C. This value was 170% higher than that of AgI at its melting point.

K.Shahi, J.B.Wagner: Journal of the Physics and Chemistry of Solids, 1982, 43[8], 713-22

 

 

Table 15

Ionic Conduction Parameters for AgBr-AgI

 

AgI (mol%)

Temperature (C)

σo (S/cm)

Q (eV)

0

110-250

8.76 x 104

0.79

2

120-300

1.23 x 105

0.79

5

120-300

2.47 x 105

0.79

10

125-285

1.58 x 105

0.75

20

100-235

1.21 x 105

0.69

20

235-380

1.59 x 107

0.90

25

105-215

1.92 x 105

0.69

25

215-380

2.79 x 107

0.90

30

105-215

4.20 x 105

0.69

30

215-380

6.25 x 107

0.90