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LEED studies of lead on copper (100)
Al99 Surface Science 117 (1982) 188-195 North-Holland Publishing Company
188
A LEED ANALYSIS
OF c(2 X 2)s ON Pd(100)
W. BERNDT Fritz-Huber-lnstitut
der Max-Planck-Geselischuft,
D-1000 Berlin 33, Fed. Rep. of Germunv
and R. HORA and M. SCHEFFLER Physikalisch-Technische
Bundesunstalt,
Received
1981; accepted
14 September
D-3300 Bruunschweig, Fed. Rep. of Germuny for publication
22 October
1981
The adsorption of sulphur on the Pd(lO0) surface has been studied by a LIED intensity analysis. For the clean surface we found no indication of relaxation of the top Pd layer. The analysis for the ~(2x2) sulphur overlayer system showed that the sulphur atoms adsorb in the fourfold hollow positions, with a S-Pd layer distance of 1.3 20.05 A.
196
Surface Science 117 (1982) 196-203 North-Holland Publishing Company
LEED STUDIES
OF LEAD ON COPPER (100)
W. HOESLER and W. MORITZ Institut fiir Kristullogruphie und Minerulogie, D-8000 Miinchen, Fed. Rep. of Germany Received
I3 September
I98
SFB 128, Universitiit
I ; accepted for publication
15 October
Miinchen, Theresienstrusse
41,
198 1
Lead layers on copper (100) at coverages from 0.5 to 0.6 were investigated by quantitative LEED and AES measurements and dynamical LEED calculations. Comparisons of intensity measurements with dynamical calculations for the (fi X fi)R45” structure show that the Pb atoms are adsorbed in hollow sites. The Cu-Pb distance is close to the sum of both metallic radii. The dense lead monolayer at a coverage of 0.6 exhibits a c(Sfi X fi)R45O superstructure with cmm symmetry of the diffraction pattern. Calculations for five models were performed under variation of several geometric parameters. Most analogies were found for regular arrangements of distorted (a X fi)R45’ domains, separated by antiphase boundaries. This result is in consistency with observations of poorly ordered (fi X fi)R45” antiphase domains at intermediate coverages.
188
A LEED ANALYSIS
OF c(2 X 2)s ON Pd(100)
W. BERNDT Fritz-Huber-lnstitut
der Max-Planck-Geselischuft,
D-1000 Berlin 33, Fed. Rep. of Germunv
and R. HORA and M. SCHEFFLER Physikalisch-Technische
Bundesunstalt,
Received
1981; accepted
14 September
D-3300 Bruunschweig, Fed. Rep. of Germuny for publication
22 October
1981
The adsorption of sulphur on the Pd(lO0) surface has been studied by a LIED intensity analysis. For the clean surface we found no indication of relaxation of the top Pd layer. The analysis for the ~(2x2) sulphur overlayer system showed that the sulphur atoms adsorb in the fourfold hollow positions, with a S-Pd layer distance of 1.3 20.05 A.
196
Surface Science 117 (1982) 196-203 North-Holland Publishing Company
LEED STUDIES
OF LEAD ON COPPER (100)
W. HOESLER and W. MORITZ Institut fiir Kristullogruphie und Minerulogie, D-8000 Miinchen, Fed. Rep. of Germany Received
I3 September
I98
SFB 128, Universitiit
I ; accepted for publication
15 October
Miinchen, Theresienstrusse
41,
198 1
Lead layers on copper (100) at coverages from 0.5 to 0.6 were investigated by quantitative LEED and AES measurements and dynamical LEED calculations. Comparisons of intensity measurements with dynamical calculations for the (fi X fi)R45” structure show that the Pb atoms are adsorbed in hollow sites. The Cu-Pb distance is close to the sum of both metallic radii. The dense lead monolayer at a coverage of 0.6 exhibits a c(Sfi X fi)R45O superstructure with cmm symmetry of the diffraction pattern. Calculations for five models were performed under variation of several geometric parameters. Most analogies were found for regular arrangements of distorted (a X fi)R45’ domains, separated by antiphase boundaries. This result is in consistency with observations of poorly ordered (fi X fi)R45” antiphase domains at intermediate coverages.