[Studies on the resonance nonlinear scattering of aqueous CoFe2O4 nanoparticle]

There are five resonance scattering peaks at 400, 470, 510, 800 and 940 nm for aqueous CoFe2O4 nanoparticles. It is a nonlinear scattering medium. When excited wavelength is at 330 nm, there are a Rayleigh scattering peak at 330 nm, a 1/2 fraction frequency peak at 660 nm and a 1/3 fraction frequency peak at 990 nm. It exhibits a strongest double frequency peak at 400 nm and a Rayleigh scattering peak at 800 nm as the excited wavelength is at 800 nm. The double frequency peak and the 1/2 fraction frequency peak have similar scattering property as the Rayleigh scattering peak. A new concept including gray particle and white particle has been proposed, and applied to analysis of the resonance scattering spectra of CoFe2O4 nanoparticle system.