Scanning tunneling microscopy of binary-alloy surfaces: is chemical contrast a consequence of alloying?

被引:49
作者
Hofer, WA
Ritz, G
Hebenstreit, W
Schmid, M
Varga, P
Redinger, J
机构
[1] Vienna Tech Univ, Inst Allgemeine Phys, A-1040 Vienna, Austria
[2] Vienna Tech Univ, Inst Tech Elektrochem, A-1060 Vienna, Austria
[3] Univ Vienna, Inst Phys Chem, A-1090 Vienna, Austria
关键词
alloys; density-functional calculations; nickel; platinum; rhodium; scanning tunneling microscopy;
D O I
10.1016/S0039-6028(98)00140-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
Recent STM studies achieved chemical resolution on PtRh and PtNi alloy surfaces. By a first-principles method employing the Tersoff-Hamann model, we have simulated STM scans on PtRh and PtNi(100) surfaces by calculating the apparent heights of individual surface atoms. The difference in apparent heights between Pt and Ph atoms is caused by changes in the density of states due to alloying. The simulations for the PtNi(100) surface, however. yield apparent heights of Pt and Ni atoms below atomic resolution, indicating that in the experiment, tip-sample interactions are responsible for chemical and atomic resolution. (C) 1998 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:L514 / L519
页数:6
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