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Reconstruction of t...
Abstract
Ämnesord
Stäng
- The structure of the Pt50Ni50(100) surface was investigated by low energy electron diffraction (LEED) and scanning tunnelling spectroscopy (STM). Superstructures corresponding to 12 × 1 and 19 × 1 reconstructions were observed in the LEED pattern, and these reconstructions were identified with atomic resolution by STM. The reconstructed surface layer has a quasi-hexagonal atomic mesh with almost (111) atomic density and is divided into terraces and domains the size of which can be more than a thousand ångströms. The domains are corrugated with protrusions made up by 5 × 1 subunits of the quasi-hexagonal mesh and with valleys containing depressed atoms or 2 × 1 subunits. The 12 × 1 and 19 × 1 periodicities are determined by the sequence of valleys; depending on the thermal treatment, one or the other dominates but both generally coexist on the terrace. Owing to the complexity of the structure, LEED calculations were performed for a simplified model with surface atoms situated in a planar net and uniform quasi-hexagonal meshes. We find that in both reconstructions the two surface layers are significantly enriched with platinum. The top layer enrichment is consistent with previous Auger measurements. © 1995.
Ämnesord
- NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Condensed Matter Physics (hsv//eng)
Nyckelord
- Alloys
- Low energy electron diffraction (LEED)
- Low index single crystal surfaces
- Scanning tunneling microscopy
- Surface relaxation and reconstruction
- Surface segregation
- Surface structure
- morphology
- roughness
- and topography
- Atoms
- Calculations
- Heat treatment
- Low energy electron diffraction
- Morphology
- Platinum alloys
- Relaxation processes
- Single crystals
- Surface roughness
- Atomic density
- Atomic resolution
- Quasi hexagonal atomic mesh
- Surface reconstruction
- Surface relaxation
- Surface topography
- Surface structure
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- art (ämneskategori)
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