Direct observation of low frequency confined acoustic phonons in silver nanoparticles: Terahertz time domain spectroscopy

Sunil Kumar (1, 2) , N. Kamaraju (1, 2) , B. Karthikeyan (1) , Marc Tondusson (3) , Eric Freysz (3) , A. K. Sood (1, 2)

1 Department of Physics
2 Center for Ultrafast Laser Applications
3 CPMOH - Centre de physique moléculaire optique et hertzienne

Terahertz time domain spectroscopy has been used to study low frequency confined acoustic phonons of silver nanoparticles embedded in poly(vinyl alcohol) matrix in the spectral range of 0.1 to 2.5 THz. The real and imaginary parts of the dielectric function show two bands at 0.60 THz and 2.12 THz attributed to the spheroidal and toroidal modes of silver nanoparticles, thus demonstrating the usefulness of terahertz time domain spectroscopy as a complementary technique to Raman spectroscopy in characterizing the nanoparticles.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Sunil Kumar, N. Kamaraju, B. Karthikeyan, Marc Tondusson, Eric Freysz, et al.. Direct observation of low frequency confined acoustic phonons in silver nanoparticles: Terahertz time domain spectroscopy. Journal of Chemical Physics, 2010, 133 (1), pp.014502 (1-4). ⟨10.1063/1.3456372⟩. ⟨hal-00671152⟩