Electrodeposited thin mercury films on Pt-Ir alloy electrodes

• Published in: Thin solid films 1999-07, Vol.349 (1-2), p.147-154
• Main Authors: FERTONANI, F. L, BENEDETTI, A. V, SERVAT, J, PORTILLO, J, SANZ, F
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Cross-disciplinary physics: materials science; rheology; Electrochemistry; Electrochemistry and electrophoresis; Electrodeposition; Electrodeposition, electroplating; Exact sciences and technology; General and physical chemistry; Materials science; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Study of interfaces
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(99)00168-6

Mercury thin films prepared by electrochemical deposition on Pt-Ir alloy and after partial removing of mercury at different temperatures were studied by means of an interferometric surface mapping microscope and by X-ray photoelectronic spectroscopy. Mercury film samples having mercury partially removed by anodic stripping at a potential more positive than the corresponding peak in the voltammogram were also studied using the same techniques. For blank samples the surface topographic studies showed well defined grain boundaries. Mercury film samples when heated up to different temperatures showed as material is removed and that the surface roughness decreases as the temperature increases. For samples heated up to 800 degree C the surface roughness is approximately the same that for the blank. A model for the interphase of volumetric mercury electrodeposited on a Pt-Ir alloy has been proposed using samples both electrochemically and thermally removed of their Hg coatings. The model includes a layered three-region structure, containing at least two Pt-Hg intermetallics: PtHg sub(4) and PtHg sub(2). A substrate modified region, iridium rich, has also been detected.