Abstract
Surface tension of melt is an important factor to control heat/mass transport caused by Marangoni convection during crystal growth. We introduced recent results of surface tension measurement for molten silicon and silver by oscillating droplet method using electromagnetic levitation under well controlled oxygen partial pressure, Po_2, of measured atmosphere. A very wide temperature range measurement was successfully achieved in this study. The surface tension-temperature coefficient of the melts increases when the Po_2, becomes large. For the molten silver, a boomerang shape temperature dependence of surface tension was experimentally observed at high Po_2; surface tension was increased and then decreased with increasing temperature because the Po_2, becomes less effective. From the experimental data, the surface tension of molten silver was described as functions of both Po_2, and temperature using Szyszkowski model; the measurement condition not only of temperature but also of Po_2, should be specified in future measurement of surface tension..
