Surface Tension of Molten Silver in Consideration of Oxygen Adsorption Measured by Electromagnetic Levitation

Abstract

The surface tension of molten silver was measured as a function of temperature and oxygen activity, a(sub O2), by the oscillating droplet method using electromagnetic levitation. The surface tension of molten silver was successfully measured over the very wide temperature range of 515 K. The pure state value of the surface tension was measured when a(sub O2) is lower than 5.3×10(exp -19). The surface tension shows a boomerang shape temperature dependence at a(sub O2) of 3.2×10(exp -) to 2.0×10(exp -3). The excess amount of oxygen adsorption on the molten silver was deduced from the Gibbs adsorption isotherm. The equilibrium constant, standard enthalpy, and standard entropy for the oxygen adsorption reaction on molten silver was revised, using the measurement result based on the Szyskowski model. Furthermore, the relationship between the surface tension, temperature, and a(sub O2) was also updated.