6533b7d3fe1ef96bd1261317

RESEARCH PRODUCT

Interaction of oxygen with Mo(100), Mo(110), and Mo(111) surfaces. RHEED and AES analyses of the molybdenum oxide nucleation and growth

N. FloquetO. Bertrand

subject

Reflection high-energy electron diffractionDiffusionNucleationchemistry.chemical_elementCondensed Matter PhysicsEpitaxyOxygenElectronic Optical and Magnetic MaterialsInorganic ChemistryFacetingMetalCrystallographychemistryMolybdenumvisual_artMaterials ChemistryCeramics and Compositesvisual_art.visual_art_mediumPhysical and Theoretical Chemistry

description

Abstract A study of the nucleation and growth of MoO 3 generated by interaction of oxygen with Mo(100), Mo(110), and Mo(111) single crystalline surfaces is investigated at high oxygen pressure (10 4 Pa) and low temperature (620 to 820 K). The results of RHEED and AES analyses prove that under these oxidation conditions, MoO 3 nucleates directly from the metal without intermediate formation of MoO 2 or nonstoichiometric molybdenum oxide such as Mo 4 O 11 . The structure and orientation of MoO 3 nuclei are characterized in relation with the parent molybdenum surface. On the Mo(110) and Mo(111) surfaces, which are faceting, the nucleation and growth of MoO 3 takes place by successive structural steps. On the Mo(100) surface, epitaxial relations induce the formation of MoO 3 (010) plates oriented onto the Mo surface, which stabilizes and makes passive the Mo(100) surface. The features of the nucleation and growth of MoO 3 are interpreted as linked respectively to structural relations of the metal-oxide interface and to preferential diffusion paths of oxygen through MoO 3 .

yearjournalcountryeditionlanguage
1991-07-01Journal of Solid State Chemistry
https://doi.org/10.1016/0022-4596(91)90279-q