The Role of Steps and Defects in Electron Stimulated Desorption: Oxygen on Stepped W (110) Surfaces.

Abstract

In order to examine the role of atomic steps and defects on electron stimulated desorption (ESD) phenomena, we have studied the adsorption of oxygen on a polyhedral tungsten crystal containing a W(110) flat and 4 flats having orientations 6 deg and 10 deg off the (110) plane with rows of steps parallel to the (100) and (110) directions. Upon adsorption at 300K, there is little or no ESD O(+) emission from the oxygen-covered (110) plane. In contrast, the stepped surfaces yield intense O(+) emission normal to the terraces and in 'downstep' directions, as seen using electron stimulated desorption ion angular distributions (ESDIAD). The presence of atomic steps has a major influence on sticking probability, saturation oxygen coverage and the ESDIAD patterns at all adsorption temperatures in the range 100K to greater than or approximately 1400K. Adsorption at low coordination sites appears to be a key factor in producing high ESD ion yields. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jan 20, 1980
Accession Number
ADA080908

Entities

People

  • Theodore E. Madey

Organizations

  • National Institute of Standards and Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Auger Electron Spectroscopy
  • Auger Electrons
  • Crystal Structure
  • Crystals
  • Desorption
  • Electron Beams
  • Electron Energy
  • Electron Spectroscopy
  • Electrons
  • Elements
  • Geometry
  • Ion Beams
  • Low Temperature
  • Measurement
  • Metal Oxides
  • Military Research
  • Oxides

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science and Engineering.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene