کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5396825 | 1505768 | 2008 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Investigation of trapped metallo-dielectric core-shell colloidal particles using soft X-rays
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The charging mechanisms of free silica nanoparticles coated with a thin (40Â nm) gold shell are investigated. These are excited in the soft X-ray regime at different photon energies. The results are compared to the charging behavior of neat silica particles. The absolute charge state of the particles is measured and the electron emission probability is derived. Significant differences in the charging behavior are observed due to the metal layer, especially an increased number of emitted electrons per absorbed photon. The mechanisms of particle charging in these core-shell systems are discussed at different excitation energies, reaching up to 500Â eV. They are due to secondary electron emission, the emission of photoelectrons, and the emission of electrons from rough metal surfaces. There are also significant changes in the charging current. Neat silica particles show a distinct near-edge feature in the O 1s-regime (520-580Â eV). In contrast, gold-coated particles do not show any evidence for changes in particle charge due to resonant O 1s-absorption. This implies that properties of thin films in core-shell particles can be sensitively probed by single, trapped nanoparticles.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Electron Spectroscopy and Related Phenomena - Volumes 166â167, November 2008, Pages 74-80
Journal: Journal of Electron Spectroscopy and Related Phenomena - Volumes 166â167, November 2008, Pages 74-80
نویسندگان
Christina Graf, Burkhard Langer, Michael Grimm, René Lewinski, Melanie Grom, Eckart Rühl,