Mentioning De Faria et al., 1997, Shebanova and Lazor stress that "the high density of power from a laser excitation source often poses a problem in a Raman experiment owing to its adverse effects on a sample". In the case of micro-Raman experiments, where the laser beam is focused to a spot of a few micrometers in diameter, the spot temperature can increase even by hundreds of degrees. Consequently, the shift of Raman modes changes. But we can have also "the alteration of a sample as the result of effects such as oxidation, recrystallization, order-disorder transitions (cation redistribution), phase transition or decomposition" . The iron oxides are "good absorbers" of laser radiation, and therefore "belong to materials where care has to be taken when conducting a Raman experiment". Moreover, magnetite is easily oxidized at elevated temperatures, when measurements are made "in open air containing moisture" ).