NONDESTRUCTIVE ASSESSMENT OF THE GRAIN-SIZE DISTRIBUTION OF SNO2 NANOPARTICLES BY LOW-FREQUENCY RAMAN-SPECTROSCOPY

A nondestructive methodology is reported to obtain the grain size dist ribution of SnO2 nanoparticles, with grain sizes below 10 nm, using lo w-frequency Raman scattering measurements. The position of the main lo w-frequency Raman bands depends on the grain size and can be correlate d with the spheroidal vibration modes of a spherical elastic body with ''rigid'' boundaries. The grain size distributions deduced from Raman scattering are in agreement with the direct measurements from transmi ssion electron microscopy, especially for the smaller grains. (C) 1997 American Institute of Physics.