Contribution to the study of the solid-state reaction of mercury with pure rhodium

Thermogravimetry (TG) and other analysis techniques (EDX, SEM, Mapping surface, X-ray diffraction, inductively coupled argon plasma emission spectroscopy and atomic spectrometry with cold vapor generation) were used to study the reaction of Hg with Rh. The results permitted the suggestion that, when subjected to heat, an electrodeposited Hg film reacts with Rh to form intermetallic products with different stabilities, as indicated by at least three mass loss steps. In the first step, between room temperature and 160 degrees C, only the bulk Hg is removed. From this temperature up to about 175 degrees C, the mass loss can be attributed to the desorption of a film of metallic Hg. The last step, from 175 to 240 degrees C, can be ascribed to the removal of Hg from a thin dark film of RhHg2.