Intrinsic vibrational coherence in face-centered cubic supra-crystals of silver nanocrystals: Raman scattering measurements.
J Phys Chem B
; 109(44): 21159-66, 2005 Nov 10.
Article
em En
| MEDLINE
| ID: mdl-16853741
ABSTRACT
The ordering of silver nanocrystals is tuned from amorphous aggregates to highly well-ordered, face-centered cubic supra-crystals, using various substrates and controlling their temperature to obtain this. Low-frequency Raman scattering, for the first time, demonstrates vibrational coherence in fcc supra-crystals of nanocrystals. This is shown by a narrowing of the peak corresponding to the quadrupolar modes of the nanocrystals. However, this is obtained when the supra-crystals are smaller than the excitation wavelength. When the supra-crystals are larger, the narrowing cannot be observed. Furthermore, for any size of the supra-crystals, a shift to low frequency of the Raman peak due to the Lorentz field effect is seen.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
J Phys Chem B
Assunto da revista:
QUIMICA
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
França