In Song et al., 2012, we have found that magnetite nanoparticles can be obtained by reduction from amorphous iron oxide, or as told in the article, by means of a transition "from hematite to magnetite", assisted by glucose. For glucose coated Fe3O4 nanoparticle, see Actually, Fe3O4@C nanoparticles have been obtained by , for the first time with onestep hydrothermal carbonization: "to the best of [Xuan and coworkers'] knowledge, there has been no report about the fabrication of Fe3O4@C core/shell composites via a one-step hydrothermal carbonization coreduction technique under such [given by Xuan and coworkers] temperatures". The synthesis is described as follows. Glucose, FeCl3 and urea were dissolved in water under stirring vigorously; then solution has been sealed in Teflon-sealed autoclave. "The autoclave was kept at 180 °C for 14 h before been cooled naturally". The magnetic particles were separated magnetically and dried. XRD tells that nanoparticles are made of magnetite. The Raman spectrum is provided in the Figure by Xuan and coworkers; the Raman shift starts from 500 cm -1 and therefore we have not the part of the spectrum which could indicate a laser induced oxidation. But, in the given spectrum we can see an interesting low and broad peak at about 700 cm -1 . The same bump is visible in the Figure by Song et al., 2012.