The influence of aqueous solutions of KNO3, KClO3, and KIO3 on tungsten surfaces has been investigated in terms of the degree of surface oxidation, metal dissolution and interfacial friction. The surface properties of tungsten films have been measured ex-situ with X-ray photoelectron spectroscopy and in situ with atomic force microscopy. Measurements of the surface composition reveal a greater degree of oxidation for surfaces treated in solutions of KIO3 in comparison to the other solutions. This increase in surface oxidation is correlated to a greater rate of localized film dissolution that occurs under the action of the scanning probe tip. In turn, the process of material removal is the predominant origin of the higher interfacial friction measured at tungsten surfaces immersed in KIO3 solutions, as compared to KClO3 and KNO3 solutions. Collectively, these measurements portray a fundamental pathway of material removal at tungsten surfaces in the presence of oxidizing species and highlight complementary roles of chemical and mechanical action. (C) 2003 Elsevier B.V. All rights reserved.