Atomic resolution Imaging on CeO2(111) with hydroxylated probes
Autor(en): | Gritschneder, Sebastian Reichling, Michael |
Stichwörter: | CATALYSIS; CEO2; CERIA; Chemistry; Chemistry, Physical; Materials Science; Materials Science, Multidisciplinary; MODEL; Nanoscience & Nanotechnology; SCANNING FORCE MICROSCOPY; Science & Technology - Other Topics; SURFACE | Erscheinungsdatum: | 2008 | Herausgeber: | AMER CHEMICAL SOC | Journal: | JOURNAL OF PHYSICAL CHEMISTRY C | Volumen: | 112 | Ausgabe: | 6 | Startseite: | 2045 | Seitenende: | 2049 | Zusammenfassung: | The formation of atomic contrast on the stoichiometric CeO2(111) surface imaged by dynamic scanning force microscopy (SFM) operated in the noncontact mode (NC-AFM) is investigated. We reproducibly obtain two stable contrast patterns, namely a pattern of hexagonally ordered disk-like features and a honeycomb type structure. In series of measurements where we systematically vary the tip-surface, distance, we find at a large distance exclusively disk-like contrast while the honeycomb pattern occasionally appears at a small tip-surface distance. We explain the contrast features within a model assuming that both types of contrast are created by the attractive interaction of first and third layer surface oxygen ions with the terminating cluster of the tip. We propose a tip model involving single or vicinal hydroxyl groups at the apex of a silicon oxide tip. Within this model, the disk like contrast is produced by the most protruding hydroxyl group while the reversible change in contrast found for a small tip-surface distance is caused by its relaxation and possibly further hydroxyl groups contributing to the tip sample interaction. |
ISSN: | 19327447 | DOI: | 10.1021/jp076994y |
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