Comment on 'Laser controlled magnetism in hydrogenated fullerene films' [J. Appl. Phys. 109, 083941 (2011)]

摘要

Hydrogenation of C_(60) films with formation of single hydrogen adduct reported by Makarova et al. [J. Appl. Phys. 109, 083941 (2011); Phys. Status Solidi B 246, 2778 (2009)] was supported only by several features found in Raman spectra of treated samples. However, no spectra were shown for untreated samples. Data shown in this comment prove that all Raman peaks assigned by Makarova et al. [J. Appl. Phys. 109, 083941 (2011); Phys. Status Solidi B 246, 2778 (2009)] to effects of hydrogenation can be found in spectra of pristine untreated commercial C_(60) powder. These peaks represent some second order vibrations of C_(60) as well as some possible solvent impurities. Therefore, all magnetic effects reported in this study should be assigned to unknown effects but not necessarily to hydrogenation.