Abstract
The activities of Si and Fe have been determined in the Fe-Si system at 1 600°C by the use of a combination of a mass spectrometer and a Knudsen-cell. In order to surpress the production of SiO gas, ThO2 was used for cell material.
The range of composition of Si was 0.05<Nsi<0.5, and Belton-Fruehan's equation was used to estimate the activity coefficient and the interaction coefficient, log γ°si, and εSiSi from measured ion current ratios; log γ°Si=-3.1±0.2
εSiSi=11.5±1.5
