Ferromagnetic Effects in Cr-Doped Fe2O3 Thin Films

Among various phases of iron oxide, hematite (Fe
₂
O
₃
) has attracted world attraction owing to its stability, oxidation, and corrosion resistance. Undoped and Cr-doped Fe
₂
O
₃
thin films were prepared using sol-gel spin coating method. XRD results indicate that incorporation of chromium causes contraction in the unit cell, which, according to Bragg's law, leads to shift of peak positions to higher diffraction angles. Contraction in unit cell is because of the smaller ionic radius of Cr
³⁺
as compared with iron cation. M-H curves of Cr-doped Fe
₂
O
₃
thin films show transition from weak ferromagnetic to strong ferromagnetic behavior as a function of dopant concentration. The change in magnetic properties has been correlated to the change in energies and structures of hematite with incorporation of chromium.