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DOE OSTI · 22025414

Surface modification by subsurface pressure induced diffusion

Zimmermann, Claus G
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Abstract

Polycrystalline Ag, covered with a nm thin siloxane layer, was irradiated with ultraviolet light in vacuum at 500 K. Ag particles of different aspect ratios, 50-1000 nm in size, formed on the surface, including a small fraction of nanorods. Pressurized water vapor bubbles are created in the subsurface region by hydrogen radicals photo-chemically released by the siloxane layer. They provide the driving force for a diffusive material flux along grain boundaries to the surface. This mechanism was modeled and found to agree with the experimental timescale: approximately 300 h are required for a 1000 nm particle to form.

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36 MATERIALS SCIENCE75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYASPECT RATIODIFFUSIONGRAIN BOUNDARIESHYDROGENLAYERSMODIFICATIONSNANOSTRUCTURESORGANIC COMPOUNDSPARTICLE SIZEPARTICLESPHOTOCHEMISTRYPOLYCRYSTALSRADICALSSILVERSURFACE TREATMENTSSURFACESULTRAVIOLET RADIATIONVISIBLE RADIATIONWATER VAPOR

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Zimmermann, Claus G. 2012-01-23. Surface modification by subsurface pressure induced diffusion. https://doi.org/10.1063/1.3679616

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DOE OSTI2026

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36 MATERIALS SCIENCE↗