Naslov
Raman scattering on quadrupolar vibrational modes of spherical nanoparticles

Autori
Ristić, Davor ; Ivanda, Mile ; Furić, Krešimir ; Desnica, Uroš V. ; Buljan, Maja ; Montagna, Maurizio ; Ferrari, Maurizio ; Chiasera, Andrea ; Jestin, Yoann

Izvornik
Journal of Applied Physics (0021-8979) 104 (2008), 7; 073519-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
acoustic wave velocity ; cadmium compounds ; elemental semiconductors ; germanium ; II-VI semiconductors ; nanoparticles ; Raman spectra ; transmission electron microscopy ; vibrational modes

Sažetak
The Raman light to vibrations coupling coefficients C(n) of quadrupolar and symmetrical vibrational modes of spherical nanoparticles embedded in a matrix are calculated. In contrast to the symmetrical mode, the C(n) of the quadrupolar modes consists of the longitudinal and transversal sound velocity contributions. It is shown, that depending on the ratio of longitudinal and transverse sound velocity, these two contributions can interfere constructively or destructively resulting in enhancing or vanishing of some radial modes. The calculated results were compared with the polarised Raman spectra of CdSxSe1-x and Ge nanoparticles. By using the known size distribution of the CdSxSe1-x particles found by HRTEM, the calculated low frequency (LF) polarised Raman spectra agree with the experimental. In the second case, the size distribution of Ge particles determined from the LF Raman spectra showed good agreement with the HRTEM results. The inverse problem of the determination of sound velocities of nanoparticles from the polarised low frequency Raman spectra by using the calculated C(n) and known size distribution of the nanoparticles was demonstrated for the hafnium oxide nanoparticles in a silica matrix.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA