Abstract
Gold, silver, copper and zinc can dissolve in mercury and these alloys are generally called amalgams. Liquid electric contacts by attaching little Hg with gold can establish a closed-circuit between carbon nanotubes and Hg, which is suitable for nano-scale manipulation and in-situ measurement. However, Hg vapor may contaminate vacuum chambers and cause deviation of vacuum gauges.This study focused on the reaction between Au and Hg. Gray amalgams were prepared by exposing Au wires, filaments and tungsten wires coated with Au to Hg vapor. By charging or heating these wires under different pressures, Hg vapor were evaporated and then deposited on the Au films mounted on 3 mm TEM grids. After the evaporation, the morphology and diffraction pattern of grids were examined under transmission electron microscope in order to study the feasibility of Hg evaporation in vacuum.Under TEM images, it was found that Hg didn’t form a uniform adsorption layer on Au surface. Some portions of Au film reacted with Hg and became dark island-shaped alloys. In addition to the FCC rings, there are some other spots in diffraction patterns. Au3Hg structures in island-shaped alloys were identified by comparing the radii of different rings and the positions of spots, with few spots unidentifiable. Since Au3Hg is stable at 1 atm and in vacuum, Au can be the storage and the evaporation source of Hg, which would be applied to TEM sample holder to conduct micro-scale evaporation directly.