A SIMS Study of the Influence of Low Levels of Silicon and Calcium on the Adsorption Properties of O2 on Pt(111).

Abstract

Surface impurity levels of Calcium, Silicon and Aluminum at or below the detectability limits of AES were followed in SIMS and correlated with oxygen adsorption on Pt (111). It is shown that oxidation of Silicon to Si0x, monitored by the rise in SIMS Si+ ion intensity, takes place above 5400K during oxygen TPD. Si0x starts decomposing above 1100K and can be reduced within 200 sec by 2x10 to the minus 8th power torr of H2 at 1200K. The oxygen adsorbed/desorbed in a TPD cycle depends on the immediate history of the impurity levels on the surface. Si0x presence correlates with an increase in the overall oxygen sticking coefficient. These results highlight the importance of impurity levels below AES detectability and suggest pretreatment methods for obtaining better reproducibility.

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Document Details

Document Type
Technical Report
Publication Date
Oct 15, 1985
Accession Number
ADA160699

Entities

People

  • C. M. Greenlief
  • H. -w. Chen
  • J. Michael White
  • S. Akhter

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Advanced Electronics
  • C4I

DTIC Thesaurus Topics

  • Abstracts
  • Adsorption
  • Chemistry
  • Coefficients
  • Governments
  • Impurities
  • Military Research
  • Oxidation
  • Plastic Explosives
  • Reproducibility
  • Security
  • Two Dimensional
  • United States
  • United States Government

Readers

  • Molecular Photonics/Laser Physics
  • Thin Film Deposition Science.