RHEED and STM studies of the pseudo-tenfold surface of the {xi}{sup '}-Al{sub 77.5}Pd{sub 19}Mn{sub 3.5} approximant crystal
- National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 (Japan)
- LSG2M, CNRS-UMR7584, Ecole des Mines, Parc de Saurupt, 54042 Nancy (France)
- Department of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States)
The pseudo-tenfold surface of the {xi}{sup '}-Al{sub 77.5}Pd{sub 19}Mn{sub 3.5} crystal, an approximant of the icosahedral Al-Pd-Mn quasicrystal, is investigated by reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy. The observed RHEED patterns of the surface after sputtering are found to be consistent with those of a simple cubic lattice with (110) surface plane. The [001] and [110] axes of the surface plane are oriented along the principal low-index axes of the bulk. The RHEED patterns of the sputter-annealed surface consist of diffraction streaks with periodic spacings expected for the bulk truncated surface. The surface prepared under different preparation methods is found to exhibit different step-height distribution and terrace morphology. A longer annealing yields a high density of shallow pentagonal pits on terraces, separated predominantly by 0.80-nm high steps and occasionally by double steps. In contrast, the surface prepared with shorter annealing time exhibits highly perfect terraces with 0.80-nm-high steps and additional unusual steps of heights close to 0.40 nm. All step heights observed for both preparation methods are consistent with interlayer spacings of the bulk model.
- OSTI ID:
- 20719048
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 71, Issue 22; Other Information: DOI: 10.1103/PhysRevB.71.224201; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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