Investigations on magnetic and electrical properties of Zn doped Fe_2O_3 nanoparticles and their correlation with local electronic structures

摘要

Present work aims at investigating the structural, magnetic and dielectric properties of zinc doped Fe2O3 nanoparticles (pure, 10%, 20% & 30%) and correlated with their local electronic structures using X-ray absorption near-edge structure (XANES) spectroscopy. X-ray diffraction and Raman measurements infer that doping of Zn cations lead to the formation of secondary phases corresponding to ZnFe2O4 along with the hematite phase of Fe2O3. Magnetic measurements show that magnetization vs magnetic field curve for 10% Zn doping exhibit maximum saturation magnetization (similar to 2.93 x 10(-3) emu/g) as well as the coercivity (similar to 956 Oe). The values of these parameters decrease for higher content of Zn. The temperature dependence of dielectric behaviour follows the same trend as that of the lattice parameter and magnetic measurements. The XANES spectra at Fe L- and Fe K-edges indicate partial reduction of Fe3+ ions into Fe2+ upon Zn doping in the Fe2O3 lattice. However, divalent state is favourable for Zn (i.e. Zn2+) within the doping range reported in this study.