INTERACTION OF MERCURY-VAPOR WITH THIN-FILMS OF GOLD

Thin films of gold deposited on a silicon substrate were used as elect rical sensors of mercury vapour. The samples were exposed to mercury v apour at room temperature, changing the Hg concentration and the expos ure time. The chemical composition and morphology of the films exposed to mercury vapour were studied by X-ray photoelectron spectroscopy (X PS), secondary ion mass spectroscopy (SIMS), scanning Auger microscopy (SAM) and secondary electron microscopy (SEM). In the samples exposed for a short time, the mercury was adsorbed by thin surface sublayer o f Au film. In the case of long exposures, the transformation of the un iform Au film to a dendritic-like coalesced AuHg amalgam occurred, i.e . the morphology of the film was modified irreversibly. This transform ation is caused by insufficient adhesion of gold to the substrate.