Growth, structure and chemical properties of FeO overlayers on Pt(100) and Pt(111)

• Published in: Surface science Vol. 268; no. 1; pp. 170 - 178
• Main Authors: Vurens, G.H., Maurice, V., Salmeron, M., Somorjai, G.A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1992; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface and interface dynamics and vibrations; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Crystal growth; Stoichiometry; Oxide layer; Chemical stability; Crystal face; Experimental study; Inorganic compound; Thin film; Surface structure; Iron Oxides; Ion scattering; Growth mechanism; LEED diffraction; Photoelectron spectrometry; Chemical properties; Auger electron spectrometry; Crystalline structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(92)90960-E

Iron oxide was deposited on Pt(111) and Pt(100). In both cases the growth mode appears to be layer-by-layer for the first few layers, as indicated by Auger and ion scattering spectroscopies. Ordered structures were formed after annealing as indicated by LEED with (10 × 10) and c(2 × 10) expitaxial relationships respectively. The Fe/Pt atomic ratio was the same for both substrates and the stoichiometry was approximately Fe: O = 1:1, with the (100) substrate containing less O relative to Fe than the (111) substrate. The oxidation state of Fe is + 2 according to XPS. A model is proposed for both overlayers consisting of an FeO(111) bilayer of Fe 2+ and O 2−. The chemical properties of these two oxide monolayers were found to be similar in regard to H 2O adsorption, but very different toward CO chemisorption. Their stability towards alkali metal deposition was found to be different also.