Electron energy loss spectra and Auger spectra of thin films on transition metal substrates.
Item
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Title
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Electron energy loss spectra and Auger spectra of thin films on transition metal substrates.
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Identifier
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AAI9417514
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identifier
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9417514
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Creator
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Wu, Zhibiao.
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Contributor
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Adviser: J. M. Dickey
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Date
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1994
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Condensed Matter
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Abstract
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Al is an ideal metal for studying the electron energy loss spectra (EELS) since both bulk and surface plasmons are prominent and are well explained by a nearly free electron model. For the transition metals, on the other hand, the situation is complicated by d-band effects. Thin films of Al and Sn have been grown on the transition metals Nb, Mo and Ta as substrates. The EELS measurements have been taken during the growth and annealing of the films. For very thin films we see a transition from the characteristic Al (Sn) spectra and the appearance of extra structures which may be associated with the interface between the transition metal and the films.;Several Sn films were studied to investigate the growth mechanism, thermal stability, and possible alloy formation during the anneals. A similar four-stage annealing behaviour of Sn films on the substrates Nb and Mo was observed in both the AES and the EELS spectra. There were the systematic shifts of the break points, for changing from one stage to another, to higher temperatures when the thickness of the film increases. The initial stages of the growth of a Sn film on a clean Nb substrate have been examined for comparison with the theoretical models, which have been proposed for the different modes in which a film may grow depending on the relative surface energies of the adsorbate and substrate. The experimental data have been displayed as an AA-t (Auger Amplitude versus deposition time) plot, which is consistent with the Stranski-Krastanov (SK) model and from which the attenuation length of the electrons has been determined.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
