| Numéro |
J. Phys. Colloques
Volume 47, Numéro C2, Mars 1986
32 nd International Field Emission Symposium / 32ème Symposium International d'Emission de Champ
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| Page(s) | C2-375 - C2-379 | |
| DOI | https://doi.org/10.1051/jphyscol:1986258 | |
32 nd International Field Emission Symposium / 32ème Symposium International d'Emission de Champ
J. Phys. Colloques 47 (1986) C2-375-C2-379
DOI: 10.1051/jphyscol:1986258
The Pennsylvania State University, Physics Department, University Park, Pa 16802, U.S.A.
J. Phys. Colloques 47 (1986) C2-375-C2-379
DOI: 10.1051/jphyscol:1986258
AN ATOM-PROBE STUDY OF COMPOSITIONAL VARIATIONS IN THE NEAR-SURFACE LAYERS OF BINARY ALLOYS
M. AHMAD et T.T. TSONGThe Pennsylvania State University, Physics Department, University Park, Pa 16802, U.S.A.
Abstract
Quantitatively reliable equilibrium composition depth profiles with true single atomic layer depth resolution have been obtained for the (001) plane of a Pt-Ir and five Pt-Rh alloys. Pt segregates to the top two layers in Pt-Ir alloy. Pt concentration decreases monotonically towards the bulk value. Rh segregates to the top layer in Pt-Rh alloys and the concentration profile is oscillatory. In addition, cosegregation of impurity sulfur (less than 100 ppm in the bulk) and formation of a chemisorbed overlayer has been observed.