Hematite Raman Spectrum

Fe₂O₃ is widely known as hematite – the primary source of iron for the steel production industry. Its most common form, α-Fe₂O₃, has a rhombohedral structure. Below 260 K, this compound is antiferromagnetic, whereas above this temperature, it exhibits weak ferromagnetism, up to 950 K (Néel temperature). The synthesis of hematite particles (α-Fe₂O₃) of different shapes and sizes has been studied thoroughly because of their new physical and chemical properties compared to bulk materials. Fe₂O₃ nanoparticles are also of great interest due to their potential applications in inorganic pigments, catalysts, humidity and gas sensors, photoelectrolysis reactors, photoanodes in photo-electrochemical cells, water treatment, lithium-ion batteries, etc.

Raman spectroscopy of Fe₂O₃

Pure Fe₂O₃ belongs to the R-3c crystal space group. Hence, according to group theory, the pure hematite Raman spectrum is expected to contain seven phonon lines. Also, the shifts in the spectral peaks reveal the difference in the shapes and sizes of the nanoparticles. Therefore, Raman spectroscopy is a useful tool for characterizing Fe₂O₃ nanoparticles.