Abstract
Oxygen-induced p(3 × 1) reconstruction of a Pt0.25Rh0.75(100) alloy surface was studied by scanning tunneling microscopy (STM). When a Pt-enriched (1 × 1) Pt-Rh(100) alloy surface was exposed to O2, a clear p(3 × 1) LEED pattern appeared at temperatures higher than ca. 400 K, and segregation of Rh atoms was observed by STM. Once the p(3 × 1) Pt-Rh(100) surface is established at T≥400 K, a reversible interconversion, p(3 × l)→p(1 × 1) by H2 and p(1 × 1)→p(3 × 1) by O2, is brought about at room temperature. The p(3 × 1) surface showed three different STM images, depending on the tip condition, from which a model structure was deduced. The first formation of the p(3 × 1) structure requires the segregation of Rh atoms, but the interconversion between the p(3 × 1) and p(1 × 1) structures is responsible for the oxygen-induced array of Rh atoms along the 〈011〉directions.
| Original language | English |
|---|---|
| Pages (from-to) | 109-114 |
| Number of pages | 6 |
| Journal | Surface Science |
| Volume | 355 |
| Issue number | 1-3 |
| DOIs | |
| Publication status | Published - 1996 Jun 1 |
| Externally published | Yes |
Keywords
- Alloys
- Hydrogen
- Low index single crystal surfaces
- Oxygen
- Platinum
- Rhodium
- Scanning tunneling microscopy
- Surface structure, morphology, roughness, and topography
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry