The diffusion of the 35S radioisotope in -phase polycrystals was studied at temperatures ranging from 848 to 893K, under S vapor pressures of 5.6 x 10-6 to 3.2 x 10-4Pa, using autoradigraphy and tracer sectioning methods. It was found that the bulk diffusion was the main S transport process. The activation energy for diffusion was 190kJ/mol (table 3). Under the conditions which were used, the predominant anionic point defects were singly-ionized vacancies and quasi-free electrons.

J.Gilewicz-Wolter, Z.Zurek, A.Ochonski: Solid State Communications, 1997, 102[5], 397-400

 

 

 

 

Table 3

Tracer Diffusion Coefficients of 35S in -Ni3S2

 

 

Temperature (K)

 

PS2(Pa)

 

Method

 

D (cm2/s)

 

 

848

 

3.2 x 10-5

 

sectioning

 

2.7 x 10-11

860

3.2 x 10-5

photometry

4.0 x 10-11

873

3.2 x 10-5

sectioning

5.8 x 10-11

893

3.2 x 10-5

sectioning

1.0 x 10-10

893

3.2 x 10-5

photometry

1.1 x 10-10

893

1.0 x 10-4

photometry

8.0 x 10-11

893

3.2 x 10-4

photometry

6.0 x 10-11