Synthesis, Structures and Properties of the Cerium Doped Hematite Co-existing with CeO₂

Abstract

Cerium doped hematite powders obtained by polymeric complex method following the hydrolysis of FeCl₃·6H₂O and Ce(NH₄)₂(NO₃)₆. X-ray diffraction pattern of cerium doped samples obtained at 1000°C∼1200°C for two hours in air revealed some solubility of cerium ion in α-Fe₂O₃ over the composition range of 5%∼15 at% that were characterized by the shifting of X-ray diffraction peaks compared with the internal silicon standard. X-ray Photoelectron Spectra investigations revealed the existence of Ce³⁺ ion at higher temperature. Unit cell parameters were found to expand due to the incorporation of cerium ions into the hematite lattice. Field Emission Scanning Electron Microscopy studies showed that the growth of particles was suppressed in the appearance of cerium ions into the α-Fe₂O₃ lattice. Fe_2-xCe_xO₃ exhibits much lower magnetization due to the incorporation of non-magnetic cerium ions into the α-Fe₂O₃. Spectroscopy measurement evidenced that cerium doped hematite samples exhibited brighter yellowish red color tone than that of pure α-Fe₂O₃.