Step-edge segregation of bimetallic alloys -: A LEIS study of Pt25Rh75(410)

被引：21

作者：

Moest, B

Wouda, PT

van der Gon, AWD

Langelaar, MC

Brongersma, HH

Nieuwenhuys, BE

Boerma, DO

机构：

[1] Eindhoven Univ Technol, Fac Phys, NL-5600 MB Eindhoven, Netherlands

[2] Leiden Univ, Leiden Inst Chem, Dept Heterogeneous Catalysis & Surface Sci, NL-2300 RA Leiden, Netherlands

[3] Univ Groningen, Ctr Mat Sci, NL-9747 AG Groningen, Netherlands

来源：

SURFACE SCIENCE | 2001年 / 473卷 / 03期

关键词：

alloys; vicinal single crystal surfaces; surface segregation; platinum; rhodium; ion scattering spectroscopy; low energy ion scattering; ion-solid interactions;

D O I：

10.1016/S0039-6028(00)00964-X

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We demonstrate that low energy ion scattering can be used to study the step-edge composition on vicinal single crystal surfaces. Employing the shadowing and focusing effects inherent to ion scattering, it is possible to perform site-specific composition measurements on single crystal surfaces over a wide temperature range. By combining these measurements with ion trajectory simulations we have extracted quantitative information concerning the step-edge composition. This technique has been applied to the Pt25Rh75(4 1 0) surface in the temperature range between 400 degreesC and 700 degreesC, The experiments reveal a much stronger Pt enrichment of the step edges than at the terrace sites. This difference between the step-edge composition and the terrace site composition is significantly larger than predicted by simple segregation models based on bond breaking. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：159 / 171

页数：13

共 36 条

[1] RECENT DEVELOPMENTS IN LOW-ENERGY ION-SCATTERING SPECTROSCOPY (ISS) FOR SURFACE STRUCTURAL-ANALYSIS [J].