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Revealing the nanoparticles aspect ratio in the glass-metal nanocomposites irradiated with femtosecond laser.

Chervinskii S, Drevinskas R, Karpov DV, Beresna M, Lipovskii AA, Svirko YP, Kazansky PG - Sci Rep (2015)

Bottom Line: Comparing experimental absorption spectra with the modeling based on Maxwell Garnett approximation modified for spheroidal inclusions, we obtained the mean aspect ratio of the re-shaped silver nanoparticles as a function of the laser fluence.We demonstrated that under our experimental conditions the spherical shape of silver nanoparticles changed to a prolate spheroid with the aspect ratio as high as 3.5 at the laser fluence of 0.6 J/cm2.The developed approach can be employed to control the anisotropy of the glass-metal composites.

View Article: PubMed Central - PubMed

Affiliation: Institute of Photonics, University of Eastern Finland, P.O.Box 111 Joensuu, FI-80101 Finland.

ABSTRACT
We studied a femtosecond laser shaping of silver nanoparticles embedded in soda-lime glass. Comparing experimental absorption spectra with the modeling based on Maxwell Garnett approximation modified for spheroidal inclusions, we obtained the mean aspect ratio of the re-shaped silver nanoparticles as a function of the laser fluence. We demonstrated that under our experimental conditions the spherical shape of silver nanoparticles changed to a prolate spheroid with the aspect ratio as high as 3.5 at the laser fluence of 0.6 J/cm2. The developed approach can be employed to control the anisotropy of the glass-metal composites.

No MeSH data available.


(a) Absorbance of the non-modified GMN calculated using MGA (black solid line) and obtained in the experiment (wide grey line). (b) Solid lines represent differential optical density of the GMN after laser irradiation with fluence of 0.375 J/cm2 (black), 0.5 J/cm2 (red), and 0.625 J/cm2 (blue). Dash lines represent differential optical density of the GMN calculated using MGA upon c/a = 3.32, ξ = 0.37 (black); c/a = 3.61, ξ = 0.38 (red), and c/a = 3.74, ξ = 0.31 (blue). Inset shows nanoparticles inside the laser modified sample. (с) Simulated spectrum of the differential optical density vs aspect ratio and resonance wavelength for ξ = 0.31. The following parameters were used for the numerical simulations:  =4, λp =135 nm, γ/ωp = 0.09, L = 10 nm, f = 0.06, αs = 0.016 nm−1, the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65, respectively.
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f6: (a) Absorbance of the non-modified GMN calculated using MGA (black solid line) and obtained in the experiment (wide grey line). (b) Solid lines represent differential optical density of the GMN after laser irradiation with fluence of 0.375 J/cm2 (black), 0.5 J/cm2 (red), and 0.625 J/cm2 (blue). Dash lines represent differential optical density of the GMN calculated using MGA upon c/a = 3.32, ξ = 0.37 (black); c/a = 3.61, ξ = 0.38 (red), and c/a = 3.74, ξ = 0.31 (blue). Inset shows nanoparticles inside the laser modified sample. (с) Simulated spectrum of the differential optical density vs aspect ratio and resonance wavelength for ξ = 0.31. The following parameters were used for the numerical simulations:  =4, λp =135 nm, γ/ωp = 0.09, L = 10 nm, f = 0.06, αs = 0.016 nm−1, the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65, respectively.

Mentions: In order to reveal the parameters of nanocomposite we performed fitting of measured linear absorption spectrum of the non-modified GMN. In the fitting, we used conventional Drude model parameters for silver,  = 4, λp = 135 nm, γ/ωp = 0.0923, and assumed that the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65. This difference in the refractive indices originates both from the ion exchange and increase of silver ions concentration in the subsurface region of glasses in the course of the hydrogen processing1920. The scattering losses in the subsurface layer were taken into account phenomenologically by introducing extinction coefficient αs = 0.0016 nm−1. One can observe from Fig. 6(a) that we obtain a good agreement between the calculated (solid line) and measured (broad grey line) spectra upon the f = 0.06 and the thickness of silver-enriched layer L = 100 nm.


Revealing the nanoparticles aspect ratio in the glass-metal nanocomposites irradiated with femtosecond laser.

Chervinskii S, Drevinskas R, Karpov DV, Beresna M, Lipovskii AA, Svirko YP, Kazansky PG - Sci Rep (2015)

(a) Absorbance of the non-modified GMN calculated using MGA (black solid line) and obtained in the experiment (wide grey line). (b) Solid lines represent differential optical density of the GMN after laser irradiation with fluence of 0.375 J/cm2 (black), 0.5 J/cm2 (red), and 0.625 J/cm2 (blue). Dash lines represent differential optical density of the GMN calculated using MGA upon c/a = 3.32, ξ = 0.37 (black); c/a = 3.61, ξ = 0.38 (red), and c/a = 3.74, ξ = 0.31 (blue). Inset shows nanoparticles inside the laser modified sample. (с) Simulated spectrum of the differential optical density vs aspect ratio and resonance wavelength for ξ = 0.31. The following parameters were used for the numerical simulations:  =4, λp =135 nm, γ/ωp = 0.09, L = 10 nm, f = 0.06, αs = 0.016 nm−1, the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562248&req=5

f6: (a) Absorbance of the non-modified GMN calculated using MGA (black solid line) and obtained in the experiment (wide grey line). (b) Solid lines represent differential optical density of the GMN after laser irradiation with fluence of 0.375 J/cm2 (black), 0.5 J/cm2 (red), and 0.625 J/cm2 (blue). Dash lines represent differential optical density of the GMN calculated using MGA upon c/a = 3.32, ξ = 0.37 (black); c/a = 3.61, ξ = 0.38 (red), and c/a = 3.74, ξ = 0.31 (blue). Inset shows nanoparticles inside the laser modified sample. (с) Simulated spectrum of the differential optical density vs aspect ratio and resonance wavelength for ξ = 0.31. The following parameters were used for the numerical simulations:  =4, λp =135 nm, γ/ωp = 0.09, L = 10 nm, f = 0.06, αs = 0.016 nm−1, the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65, respectively.
Mentions: In order to reveal the parameters of nanocomposite we performed fitting of measured linear absorption spectrum of the non-modified GMN. In the fitting, we used conventional Drude model parameters for silver,  = 4, λp = 135 nm, γ/ωp = 0.0923, and assumed that the refractive indices of the bare and silver-enriched glass are 1.5 and 1.65. This difference in the refractive indices originates both from the ion exchange and increase of silver ions concentration in the subsurface region of glasses in the course of the hydrogen processing1920. The scattering losses in the subsurface layer were taken into account phenomenologically by introducing extinction coefficient αs = 0.0016 nm−1. One can observe from Fig. 6(a) that we obtain a good agreement between the calculated (solid line) and measured (broad grey line) spectra upon the f = 0.06 and the thickness of silver-enriched layer L = 100 nm.

Bottom Line: Comparing experimental absorption spectra with the modeling based on Maxwell Garnett approximation modified for spheroidal inclusions, we obtained the mean aspect ratio of the re-shaped silver nanoparticles as a function of the laser fluence.We demonstrated that under our experimental conditions the spherical shape of silver nanoparticles changed to a prolate spheroid with the aspect ratio as high as 3.5 at the laser fluence of 0.6 J/cm2.The developed approach can be employed to control the anisotropy of the glass-metal composites.

View Article: PubMed Central - PubMed

Affiliation: Institute of Photonics, University of Eastern Finland, P.O.Box 111 Joensuu, FI-80101 Finland.

ABSTRACT
We studied a femtosecond laser shaping of silver nanoparticles embedded in soda-lime glass. Comparing experimental absorption spectra with the modeling based on Maxwell Garnett approximation modified for spheroidal inclusions, we obtained the mean aspect ratio of the re-shaped silver nanoparticles as a function of the laser fluence. We demonstrated that under our experimental conditions the spherical shape of silver nanoparticles changed to a prolate spheroid with the aspect ratio as high as 3.5 at the laser fluence of 0.6 J/cm2. The developed approach can be employed to control the anisotropy of the glass-metal composites.

No MeSH data available.