Measurement of the surface tension of liquid Ga, Bi, Sn, In and Pb by the constrained drop method

The effect of the droplet size on the accuracy of surface tension measurement by the sessile drop method is discussed for liquid metals through a simulation by using the Laplace equation. It is found that with increasing size of the droplet, a higher accuracy of the measured value of the surface tension can be obtained. In order to make a large droplet of liquid metals, the constrained drop method with a special crucible shape was applied to measure the surface tension of liquid Ga, Sn, Bi, In, and Pb. The uncertainty of the measured surface tension was within 1%. The temperature dependences of the surface tension of liquid Ga, Sn, Bi, In, and Pb were obtained in the present experiment as follows: Ga: sigma(Ga) = 737 - 0.062T mN/m (823 less than or equal to T less than or equal to 993K) Sn: sigma(Sn) = 579 - 0.066T mN/m (723 less than or equal to T less than or equal to 993K) Bi: sigma(Bi) = 417 - 0.070T mN/m (773 less than or equal to T less than or equal to 873K) In: sigma(In) = 600 - 0.082T mN/m (673 less than or equal to T less than or equal to 993K) Pb: sigma(Pb) = 499 - 0.089T mN/m (757 less than or equal to T less than or equal to 907K)