engleski

Determination of nanosized particles distribution by low freqyency Raman scattering: Comparison to electron microscopy

The methodology for the determination of a nanosized particle distribution by low frequency Raman spectroscopy is described. It is based on a omega¨-1 dependence of the Raman light of the vibration coupling coefficient C(omega) and on the fact that each nanocrystalite of diameter D vibrates with its eigenfrequency omega=cost*1/D. The effect of the particle vibrational lifetime on the shape of the distribution is analyzed and found to be negligible for free TiO2 nanoparticles. The size distributions of TiO2 nanoparticles estimated by Raman spectroscopy were compared to those obtained by transmission electron microscopy including dark field and high resolution imaging. The Raman spectroscopy was shown to be a simple, fast method that has favourable statistics due to a macroscopic probe volume and makes in situ measurements.

size distribution, HRTEM, TEM, Raman, TiO2, low wavenumber Raman

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