Influence of Oxygen Partial Pressure on the Surface Tension of Liquid Bismuth

Abstract

The surface tension of liquid Bi has been investigated by the sessile drop method in the temperature range 573–1173 K, and an oxygen partial pressure ranging from logP_O2(Pa)≈−49 to logP_O2(Pa)≈1. The surface tension obtained was 377 mJ·m⁻² at the melting point (544 K). The temperature coefficient of surface tension over the investigated temperature range was −0.09 mJ·m⁻² K⁻¹. It has been found that the surface tension of pure liquid Bi at low oxygen pressure was nearly constant at 873 K, and the surface tension decreased from 348 mJ·m⁻² at oxygen pressure values lower than 10⁻⁸ Pa, to 320 mJ·m⁻² at P_O2≈10 Pa. The results obtained for the surface tension values and temperature coefficient are compared with those in the literature.