Temperature dependence of surface tension and capillary waves at liquid metal surfaces

The temperature dependence of the surface tension gamma(T) is treated theoretically and experimentally. The theoretical model based on the Gibbs thermodynamics of a one-component fluid relates partial derivative gamma/partial derivative T to the surface excess entropy density -Delta S. All specific surface effects, namely ordering, capillary waves, and double layer influence the surface entropy, which in turn governs the sign and the magnitude of partial derivative gamma/partial derivative T. Experimental data collected at a free Hg surface in the temperature range from 0 degrees C to 30 degrees C show that partial derivative gamma/partial derivative T is negative. (C) 1998 American Institute of Physics. [S1063-7761(98)00912-3].