The (111) Surface of NaAu2: Structure, Composition, and Stability

Date
2015-01-01
Authors
Huang, Wenyu
Thiel, Patricia
Kwolek, Emma
Widmer, Roladn
Gröning, Oliver
Deniz, Okan
Schlagel, Deborah
Walen, Holly
Yuen, Chad
Huang, Wenyu
Schlagel, Deborah
Wallingford, Mark
Thiel, Patricia
Journal Title
Journal ISSN
Volume Title
Publisher
Source URI
Altmetrics
Research Projects
Organizational Units
Chemistry
Organizational Unit
Journal Issue
Series
Abstract

The (111) surface of single-crystal NaAu2 is a model for catalytically active, powdered NaAu2. We prepare and characterize this surface with a broad suite of techniques. Preparation in ultrahigh vacuum consists of the traditional approach of ion bombardment (to remove impurities) and thermal annealing (to restore surface order). Both of these steps, however, cause loss of sodium (Na), and repeated treatments eventually trigger conversion of the surface and near-surface regions to crystalline gold. The bulk has a limited ability to repopulate the surface Na. Under conditions where Na depletion is minimized, electron diffraction patterns are consistent with the bulkterminated structure, and scanning tunneling microscopy reveals mesa-like features with lateral dimensions of a few tens of nanometers. The tops of the mesas do not possess fine structure characteristic of a periodic lattice, suggesting that the surface layer is disordered under the conditions of these experiments.

Description
<p>Reprinted (adapted) wit permission from <em>Inorganic Chemistry</em> 54 (2015): 1159, doi:<a href="http://dx.doi.org/10.1021/ic5025444" target="_blank"> 10.1021/ic5025444</a>. Copyright 2014 American Chemical Society.</p>
Keywords
Ames Laboratory, Materials Science & Technology
Citation
Collections