The Variation of Absorption Edges of X-Rays for Liquid Hg-Rb Alloys

Abstract

The L_I and L_III edges of Hg and the K edge of Rb in liquid Hg-Rb alloys were measured by the absorption spectroscopy of X-rays. On increasing the Rb concentration, the absorption edges of Hg show an opposite behavior each other, the decrease of L_I and the increase of L_III compared with the case of pure liquid Hg. This difference was discussed from the polyanion formation of Hg atoms on alloying. With the increase of alkali concentration, the p like state or polyanion seems to be situated on the lower energy side than that of s band. The electronic structure of this polyanion was discussed based on a simple LCAO analysis. Such an existence of polyanions may be responsible to the curious phenomena of liquid Hg-alkali alloys, the maximum of the electrical resistivity at 60 at% alkali and the positively enhanced tendency in the intermediate alkali concentration range of the magnetic susceptibility in the overall negative deviation.