Event 

Title:
Seminarios en el Acelerador - Más allá del mecanismo de conformación de haces de iones: hacia la aplicación plasmónica
When:
22.11.2013 - 22.11.2013
Where:
CMAM - Madrid
Categoría:
Seminarios informales en el Acelerador

Description

Ponente: Giancarlo Rizza, Laboratoire des Solides Irradiés LSI, École Polytechnique, Francia

Título:Más allá del mecanismo de conformación de haces de iones: hacia la aplicación plasmónica

Abstract: In the last years, ion-shaping technique has been proposed as an innovative and powerful tool to manipulate matter at the nanometer scale [1-3]. Deformation can be indirectly induced by embedding metallic NPs into an ion-deformable amorphous host matrix.

A model system composed of nearly monodisperse metallic nanoparticles (NPs) (8-100nm) confined between two silica layers is used to investigate the ion-shaping mechanism. We show that this phenomenon is not limited to the transformation into prolate nanorods and/or nanowires, but that depending on the initial size of the NPs, several new classes of ion-shaped NPs can also be obtained: i) facetted-like NPs,  ii) nanowires growing from a facetted core or iii) chromosome-like NPs. In parallel, the evolution of the temperature profile within the nanoparticle is simulated by implementing the thermal-spike model for three-dimensional anisotropic and composite media [4]. In this way, a clear correlation is found between the fraction of the nanoparticle that is molten(vaporized) and the deformation path followed by the nanoparticles during the irradiation. This allows the construction of a size-vs-shape diagram relating the initial nanoparticle size to its final morphology. This diagram is used to give a rational description of the ion-beam shaping process for all the nanoparticle dimensions [5].

Besides the fundamental aspects related to the ion-matter interaction, ion-shaping can also be used to give new insights into the plasmonic properties of metallic nanorods and nanowires. Here, Electron Energy Loss Spectroscopy (EELS) is used to study Localized Surface Plasmon Resonances (LPSR) in ion-shaped metallic nanoparticles with a nanometer-scale spatial resolution, [6]. LSPR are generated through electron excitation is a Scanning Transmission Electron Microscope (STEM), equipped with a High Angle Annular Dark Field (HAADF) detector. As the NPs are continuously deformed under irradiation, we investigate the LPSRs dependence on both the geometry and aspect ratio of the nanostructure. Finally, the experimental results are simulated using a specifically developed Auxiliary Differential Equations-Finite Difference Time Domain (ADE-FTDT) code, [7].

This work demonstrates the possibility to use ion irradiation as tool for the controllable fabrication of a whole family of plasmonic nanostructures with topologically tunable optical properties. These ion-beam shaped composite media have potential applications spanning from plasmonic photovoltaics, to bio-sensing, SERS and SEIRA spectroscopies.

G.Rizza1)*, P.E. Coulon1), A.Slablab1), J. Amici1), S.Perruchas2), T.Gacoin2), I.Monnet3), C.Dufour3), V. Khomenkov3), J.Cardin3), A.Fafin3), M.Kociak4), A. Losquin4), D.Mailly5), C.Ulysse5), X. Lafosse5)

1) LSI, Ecole Polytechnique, 91128 Palaiseau Cedex, France, 2) LPMC, Ecole Polytechnique, 91128 Palaiseau Cedex, France, 3) CIMAP, 14070 Caen Cedex 5, France, 4) LPS, Bâtiment 510, Université Paris Sud XI, F 91405 Orsay, France, 5) LPN, 91460 Marcoussis, France

References:

[1] E.A. Dawi et al, J. Appl. Phys. 105 (2009) 074305

[2] G. Rizza et al, Appl. Phys. Lett. 95 (2009) 043105

[3] M.C. Ridgway et al, Phys. Rev. Lett. 106 (2011) 095505

[4] C. Dufour, J. Phys. D Appl. Phys. 45 (2012) 065302

[5] G.Rizza et al, Phys. Rev B 86 (2012) 035450

[6] J.Nelayah el al, Nature Physics 2 (2007) 348

[7] J. Cardin et al (submitted) 

 

Venue

CMAM
Venue:
CMAM   -   Website
Street:
Faraday 3, Campus de Cantoblanco
ZIP:
28049
City:
Madrid
Country:
Country: es

Description

El seminario tendrá lugar en la sala de reuniones del CMAM