Laser induced enhancement of dichroism in supported silver nanoparticles deposited by evaporation at glancing angles.
Nanotechnology
; 24(4): 045301, 2013 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-23291348
ABSTRACT
Silver nanoparticles (NPs) depicting well defined surface plasmon resonance (SPR) absorption were deposited on flat substrates by physical vapor deposition in a glancing angle configuration. The particles were characterized by scanning electron microscopy and atomic force microscopy and their optical properties examined by UV-vis absorption spectroscopy using linearly polarized light. It was found that, depending on the amount of deposited silver and the evaporation angle, part of the 'as-prepared' samples present NPs characterized by an anisotropic shape and a polarization dependent SPR absorption and different colors when using polarized white light at 0° and 90°. Low-power irradiation of these materials with an infrared Nd-YAG nanosecond laser in ambient conditions produced an enhancement in such dichroism. At higher powers, the dichroism was lost and the SPR bands shifted to lower wavelengths as a result of the reshaping of the silver NPs in the form of spheres. The possible factors contributing to the observed changes in dichroism are discussed.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Prata
/
Dicroísmo Circular
/
Cristalização
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Nanopartículas Metálicas
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Lasers
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article