Surface segregation of core atoms in core-shell structures

被引：32

作者：

Ramirez-Caballero, Gustavo E. ^{[1
]}

Balbuena, Perla B. ^{[1
]}

机构：

[1] Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA

来源：

CHEMICAL PHYSICS LETTERS | 2008年 / 456卷 / 1-3期

关键词：

D O I：

10.1016/j.cplett.2008.03.008

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：

Density functional theory is used to calculate surface segregation tendencies of iridium atoms in Ir (core)-Pt (shell) systems with various shell thicknesses, on clean surfaces and under 1/4 monolayer of atomic oxygen adsorbed on fcc and hcp sites of (111) surfaces. Iridium shows strong antisegregation behavior in clean surfaces, but the behavior reverts dramatically in the presence of adsorbed oxygen. On Pt-skin surfaces, where the oxygen adsorption is the weakest, monolayers have better protective effect against segregation of the less noble metal, and the effect decreases as the number of layers in the shell increases. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：64 / 67

页数：4

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