ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 64.75+g  (1)
  • activation barriers  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 29 (1982), S. 141-145 
    ISSN: 1432-0630
    Keywords: 61.80Jh ; 61.70Tm ; 64.75+g
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Ion-beam mixing by 500-keV xenon ions has been studied in targets consisting of 2000-Å films of aluminium on a polycrystalline aluminium substrate, onto which has been evaporated a 500-Å overlayer of copper. Both long- and short-range-mixing processes have been identified, by RBS analysis of the irradiated targets, as a deep copper tail in the aluminium and interfacial broadening, respectively. The long-range component varies linearly with xenon fluence, is temperature-independent in the interval 40–500 K, and is not influenced by the presence of an interfacial oxide layer between the copper and aluminium layers. The number of long-range-mixed atoms is in agreement with theoretical estimates of the recoil mixing. The short-range mixing, which is the dominating process, has a squareroot dependence on xenon fluence and is independent of temperature between 40 and 300 K, increasing rapidly at higher temperatures. The broadening attributed to the short-range mixing is explained by interstitial diffusion within the cascade. For small xenon fluences, interfacial oxide layers inhibited both short-range mixing and thermal diffusion. Higher xenon fiuences subdued the inhibition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1572-879X
    Keywords: active sites ; surface alloys ; STM ; molecular beams ; activation barriers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This report describes a combined experimental and theoretical approach to the problem of designing surface alloys with specific chemical properties. Au-Ni(111) surface alloys were prepared and the distribution of active sites was determined by atomically resolved STM as a function of Au coverage. Using density functional theory the difference in activation energy for methane over the various sites was determined. The activity of the surface could be predicted directly by combining this information with the distribution of sites. Subsequent measurements of the activity proved this method to be quantitative and demonstrated that surface alloys with specific activity can be synthesized.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...