Influence of annealing conditions on the growth and structure of embedded Pt nanocrystals

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Date
2009-02-15
Journal Title
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Publisher
American Institute of Physics
Abstract
The growth and structure of Pt nanocrystals (NCs) formed by ion implantation in a-SiO2 has been investigated as a function of the annealing conditions. Transmission electron microscopy and small-angle x-ray scattering measurements demonstrate that the annealing ambient has a significant influence on NC size. Samples annealed in either Ar, O-2, or forming gas (95% N-2: 5% H-2) at temperatures ranging from 500 degrees C-1300 degrees C form spherical NCs with mean diameters ranging from 1-14 nm. For a given temperature, annealing in Ar yields the smallest NCs. O-2 and forming gas ambients produce NCs of comparable size though the latter induces H chemisorption at 1100 degrees C and above, as verified with x-ray absorption spectroscopy. This H intake is accompanied by a bond-length expansion and increased structural disorder in NCs of diameter >3 nm. © 2009, American Institute of Physics
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Keywords
Annealing, Chemisorption, Platinum, Silicon compounds, Transmission electron microscopy, Small angle scattering
Citation
Giulian, R., Araujo, L. L., Kluth, P., Sprouster, D. J., Schnohr, C. S., Johannessen, B., Foran, G. J. & Ridgway, M. C. (2009). Influence of annealing conditions on the growth and structure of embedded Pt nanocrystals. Journal of Applied Physics, 105(4), 8. doi:10.1063/1.3079506
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