A Moessbauer spectroscopic study of the Eu-Hg system

Samples of EuHgsub(x) (x = 1, 2, 3 and 3.6) have been prepared and characterized by chemical analysis and X-ray powder diffractometry. Evidence is presented for narrow ranges of solid solubility and together with other data it is concluded that these substances are better described as being intermetallic rather than metallic alloy in character. The Moessbauer spectroscopic study confirms that the europium exhibits a divalent core in each case. The isomer shift is dependent on the number density of europium atoms in the unit cell. This latter quantity correlates in a similar way with the computed conduction electron density at the europium nucleus. The decrease in electron density at the europium nucleus in these substances compared with that for europium metal is indicative of some degree of normal chemical bonding in these compounds. (Auth.)