DEFECT MOBILITY AND SELF-DIFFUSION IN NONSTOICHIOMETRIC MANGANOUS SULFIDE

Defect mobility and self-diffusion coefficient of cations in metal def icient manganous sulphide Mn1-yS have been calculated as a function of temperature (1073-1373 K) and sulphur activity (10(-2)-10(3) Pa) usin g the chemical diffusion- and nonstoichiometry data. It has been shown that the defect diffusion coefficient, being the direct measure of de fect mobility, does not depend on sulphur activity and is the followin g function of temperature: D-v=1.3.10(-2)exp(-76.4+/-0.5 kJ/M/RT). Sel f-diffusion coefficient of cations, in turn, has been found to be the function of temperature and sulphur activity: DMn=6.5.10(-4)p(S2)(1/6) exp(-117.9+/-0.7 kJ/M/RT).