Stability of citrate-coated magnetite and cobalt-ferrite nanoparticles under laser irradiation: a Raman spectroscopy investigation

In this paper, Raman spectroscopy was used to investigate the chemical and structural properties of citrate-coated Fe/sub 3/O/sub 4/ and CoFe/sub 2/O/sub 4/ nanoparticles. The Raman data obtained from the two samples investigated are compared with the Raman data from the literature of bulk maghemite and bulk hematite. The Raman data are used to discuss the higher structural stability of the CoFe/sub 2/O/sub 4/-based sample in comparison to the Fe/sub 3/O/sub 4/-based sample, when submitted to optical illumination at different intensities.