SURFACE CHARACTERIZATION OF AMALGAM MADE WITH HG-IN LIQUID ALLOY

When amalgam was triturated with Hg-In Liquid alloys instead of pure m ercury, the resultant amalgams released a significantly smaller amount of mercury vapor during setting. To understand the mechanisms respons ible for the drastic decrease in mercury evaporation from the In-conta ining amalgam, we used Auger Electron Spectroscopy to examine surface oxide films on amalgams made with Hg-10 wt% Ln or pure mercury. The su rface of the In-containing amalgam was rapidly covered with both indiu m and tin oxide films. Greater amounts of oxygen were found on the gam ma(1) Ag-Hg matrix in the In-containing amalgam than in the amalgam wi thout indium. The rapid formation of the oxide film contributes to a r eduction in the mercury release from the In-containing amalgam by form ing an effective barrier to evaporation.