Comparison of Calculated and Experimental Values for the Optical Reflectivity of the Liquid Alloys Hg-In, Hg-Tl, Ga-In at 25°C

Abstract

The optical reflectivity at 25°C of three liquid alloys Hg-In, Hg-TI, and Ga-In was measured in the wavelength range of 0.3 μ to 10 μ. Measurements were made at glass-metal, quartz-metal, and NaCl—metal interfaces by a method previously used for pure Hg and pure Ga. Experimental values thus obtained were compared with those obtained by calculation using the Drude free electron theory. It was found that when two metals of different chemical valence were combined, divalent Hg with trivalent In or divalent Hg with trivalent Tl, there was considerable disagreement of experimental and calculated values for the reflectivity. Moreover, the disagreement was of a different character for each of these two alloys. This result indicates that when two liquid metals each of which follows the Drude theory are combined, Hg and In for example, the resulting alloy does not necessarily follow the theory as was suggested by the early work of Kent. On the other hand, when two trivalent metals, Ga and In, were combined there was agreement of experiment and theory. Preliminary results of experimental measurements of the reflectivity of liquid In are also given.