Anomalous volume contraction of expanded mercury by the addition of impurity elements

Abstract

The mass density of dilute amalgams containing 0.2 at.% Bi and Cd has been measured using a dilatometer up to 1600 °C and 2000 bar. The temperature and pressure variations of the density are nearly the same as those for pure Hg at densities above 10 g/cm 3. However, in the density range between 10 and 7 g/cm 3, which includes the metal-non-metal (M-NM) transition region, thermal expansion of fluid Hg is considerably suppressed by the addition of impurity elements, especially by the addition of Bi. The mechanism of the electron transfer from impurity to Hg atoms is discussed.