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Characterization of Metal Alloy Systems by Scanning Tunneling Microscopy and Low‐Energy Ion Backscattering
Author(s) -
Niehus H.
Publication year - 1995
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221920211
Subject(s) - superstructure , scanning tunneling microscope , low energy ion scattering , crystallography , scattering , intermetallic , materials science , alloy , field ion microscope , adsorption , metal , ion , spectroscopy , analytical chemistry (journal) , chemistry , nanotechnology , metallurgy , oceanography , physics , organic chemistry , chromatography , geology , optics , quantum mechanics
Low‐energy ion backscattering and scanning tunneling microscopy (STM) can be used in combination to study the surface crystallography of single crystals, in particular also for alloy and ordered intermetallic compound systems. The elemental composition as well as the location of the atoms is determined by low‐energy noble gas impact collision ion scattering spectroscopy with neutral detection (NICISS). Microscopic information on an atomic scale is obtained with the help of STM. The influence of adsorption‐induced surface modifications is investigated at Cu 3 Au and compared with Cu surfaces. From the NICISS investigation the AuCu termination is inferred for clean Cu 3 Au(100) and (110). After careful preparation of the clean Cu 3 Au(110) surface the prominent (2 × 1) LEED superstructure changes into a pronounced (4 × 1) LEED pattern. The (4 × 1) structure can be explaining by row pairing of CuCu and AuAu rows in the topmost layer. Upon oxygen exposure of the Cu 3 Au compounds, Cu tends to segregate to the surface. In case of Cu 3 Au(110) a (2 × 1)O superstructure appears which is in part similar to the known added row structure obtained for Cu(110)(2 × 1)O. Comparison with the Cu(110)O surface shows, however, that the known periodically ordered structure of CuO stripes at undersaturation with oxygen does not show up at Cu 3 Au(110)‐O.