Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    SiH surface species on a SiC nanosized powder: ab initio and FT-IR studies of their behaviour under oxidation (1996)
    Springer
    Molecular engineering 6 (1996), S. 327-346 
    Details
    ISSN: 1572-8951
    Keywords: Silicon carbide ; surface oxidation ; surface species ; SiH frequency variations ; ab initio models ; oxidation mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Oxidation of silicon carbide is unavoidable due to contamination by the surrouding atmosphere. The silicon carbide surface presents SiH groups whose stretching frequency is precisely very sensitive to the silicon environment. Fourier transform infrared spectrometry combined with a specific cell makes it possible to analyze these SiH surface species in situ on a SiC nanosized powder, and to follow the shifts of the ν(SiH) frequency under controlled oxidation treatments. A decomposition of the ν(SiH) absorption band into its components shows the evolution of the frequencies as a function of the degree of oxidation. Simple ab initio models are then proposed to represent the SiH surface species according to the degree of oxidation. The validity of these models is checked by comparing the evolution of the ν(SiH) calculated frequencies with the values obtained from the decomposition analysis. It is demonstrated that the ab initio models cannot fit the experimental data as long as the oxidation mechanism is considered only as a direct carbon-oxygen substitution in the silicon environment. To obtain a satisfactory fit the oxygen diffusion inside the bulk must also be taken into account, which is in agreement with the experimental result proving that the SiC grains are not entirely covered by a silica layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00440407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Coherent multiphoton absorption: Dependency on the relative phase of two successive pulsesThe French version of this paper has been sent to the “Comptes Rendus de l'Acadéamie des Sciences” of France. (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 22 (1982), S. 999-1003 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: When a multilevel system excited by a laser pulse absorbs a cascade of photons, a second pulse of same frequency, equal duration but dephased by π takes it back to its initial state. This property can be inferred by studying the laser field system interaction matrix, using the rotating wave approximation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560220511
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...