Surface tension of a Si melt : influence of oxygen partial pressure

Abstract Surface tension of molten Si was measured by the sessile drop method in Ar atmosphere with different oxygen partial pressures. It was found that the surface tension of molten Si decreased with increasing temperature, and it was 825 mN/m at the melting point (about 1415°C) in a pure Ar atmosphere. The surface tension also decreased with increasing oxygen partial pressure in the Ar atmosphere, and the temperature coefficient of the surface tension changed from −0.1 mN/(mK) to about −0.26 mN/(mK) with increasing oxygen partial pressure from 0 to 0.319 Torr.