SURFACE-TENSION OF A SI MELT - INFLUENCE OF OXYGEN PARTIAL-PRESSURE

Surface tension of molten Si was measured by the sessile drop method i n Ar atmosphere with different oxygen partial pressures. It was found that the surface tension of molten Si decreased with increasing temper ature, and it was 825 mN/m at the melting point (about 1415 degrees C) in a pure Ar atmosphere. The surface tension also decreased with incr easing oxygen partial pressure in the Ar atmosphere, and the temperatu re coefficient of the surface tension changed from -0.1 mN/(mK) to abo ut -0.26 mN/(mK) with increasing oxygen partial pressure from 0 to 0.3 19 Torr.