In-situ observation of equilibrium transitions in Ni films; agglomeration and impurity effects.

Autor: Thron AM; Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, USA. Electronic address: AMThron@lbl.gov., Greene P; Department of Physics, University of California, Davis, CA 95616, USA., Liu K; Department of Physics, University of California, Davis, CA 95616, USA., van Benthem K; Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, USA.
Jazyk: angličtina
Zdroj: Ultramicroscopy [Ultramicroscopy] 2014 Feb; Vol. 137, pp. 55-65. Date of Electronic Publication: 2013 Nov 20.
DOI: 10.1016/j.ultramic.2013.11.004
Abstrakt: Dewetting of ultra-thin Ni films deposited on SiO2 layers was observed, in cross-section, by in situ scanning transmission electron microscopy. Holes were observed to nucleate by voids which formed at the Ni/SiO2 interface rather than at triple junctions at the free surface of the Ni film. Ni islands were observed to retract, in attempt to reach equilibrium on the SiO2 layer. SiO2 layers with 120 nm thickness were found to limit in situ heating experiments due to poor thermal conductivity of SiO2. The formation of graphite was observed during the agglomeration of ultra-thin Ni films. Graphite was observed to wet both the free surface and the Ni/SiO2 interface of the Ni islands. Cr forms surface oxide layers on the free surface of the SiO2 layer and the Ni islands. Cr does not prevent the dewetting of Ni, however it will likely alter the equilibrium shape of the Ni islands.
(© 2013 Published by Elsevier B.V.)
Databáze: MEDLINE
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