Surface tension of molten silicon measured by the electromagnetic levitation method under microgravity

The surface tension of molten silicon was measured using the electromagneti c levitation method under microgravity. The atmosphere was Ar-3 pet H-2 pur ified by Pt asbestos and magnesium perchlorate. The partial oxygen pressure is estimated to be less than 1.1 x 10(-14) Pa. The spherical droplet shape was controlled by changing the current ratio between a quadrupole coil and a dipole coil. The surface tension of molten silicon can be expressed by t he equation gamma = 735 - 0.074 (T - 1687) where gamma is the surface tension (in mN/m) and T is the temperature (in K ). The value was measured over a wide range of temperatures, from 230 K bel ow the melting point (1687 K) to 1890 K. The scatter of the measured surfac e-tension values is much less than that measured by conventional methods.