Song and coworkers continue in the following manner. "Because a laser with even very low energy can evolve numerous spurious peaks attributed to hematite in the Raman spectra of magnetite, the peaks at 300 and 410-420 cm -1 also reported in some previous studies on magnetite are relevant to an oxidation reaction during a Raman experiment". Song and coworkers are giving details about the magnetite Raman bands, which the authors are indicating in their Figure . Using glucose to prepare the nanoparticles, the researchers "figure out that the glucose treatment is definitely relevant to the phase transition from hematite to magnetite . … there is a clear change associated with the turnaround of intensity between the D band (1350 cm -1 ) and the G band (1580 cm -1 ) after the decomposition of glucose. The augmented D band compared to the G band shows us that the decomposition of glucose not only activates the phase transition of hematite to magnetite but also makes the amorphous carbon layer on the surface of the evolved magnetite iron oxide show good agreement with XRD and TEM results" . From hematite to magnetite? See Ponomar, 2018, and the discussion of magnetite prepared by chemical reduction from hematite. In Ponomar et al., 2017, the use of carbohydrates in the reduction roasting of hematite to magnetite is discussed.