De Faria and coworkers are giving experimental data in the Figures Several samples (natural and synthetic hematite) were studied by De Faria and coworkers, finding similar results, "except for changes in relative intensities that occurred when natural samples" had been considered. The researchers explain that the natural samples are much more crystalline than the synthetic samples. Then, the natural crystals are sensitive to sample orientation. Hematite is antiferromagnetic, with magnons as collective spin movements. The intense band at 1320 cm -1 is "assigned to a two-magnon scattering". "Raising the laser power to 7 mW (at the sample) causes the bands to broaden and to undergo a small shift to lower wavenumbers".