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Title: The (111) Surface of NaAu 2. Structure, Composition, and Stability

The (111) surface of single-crystal NaAu 2 is a model for catalytically active, powdered NaAu 2. 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 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 bulk-terminated 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.
 [1] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1] ;  [1] ;  [3] ;  [3] ;  [4]
  1. Iowa State Univ., Ames, IA (United States)
  2. Swis Federal Laboratories for Materials Science and Technology (Switzerland)
  3. Ames Lab., Ames, IA (United States)
  4. Iowa State Univ., Ames, IA (United States); Ames Lab., Ames, IA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
IS-J 8532
Journal ID: ISSN 0020-1669
Grant/Contract Number:
200021-129511, AC02-07CH11358
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 54; Journal Issue: 3; Journal ID: ISSN 0020-1669
American Chemical Society (ACS)
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
Country of Publication:
United States