Structural, magnetic and electrical properties of pure and Dy-doped Fe2O3 nanostructures synthesized using chemical thermal decomposition technique

Abstract

Pure (S₁) and Dy³⁺-doped α-Fe₂O₃ (S₂ and S₃) nanoparticles were prepared by a combustion synthesis method at 700 ºC for 8 h using Fe(acac)₃ (Tris(acetylacetonato)Iron(III)) as raw material. Characterizations of the prepared powders were carried out by powder X-ray diffraction (PXRD). Structural analysis was performed by the <em>FullProf</em> program employing profile matching with constant scale factors. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS), elemental maps analysis and energy-dispersive X-ray spectroscopy (EDS) were also performed to determine the dopant amount in the α-Fe₂O₃ crystal structure (S₃). The results showed that the patterns had a main hexagonal structure with space group <em>R</em> . The cell parameters data, calculated by rietveld analysis, showed that the cell parameters were decreased with increasing the dopant (Dy³⁺) amount in the α-Fe₂O₃ crystal structure. The average particles sizes estimated from TEM images for S₃ were about 60 nm. Besides, the magnetic properties of S₁ and S₃ were measured by vibrating sample magnetometer (VSM). It was found that with the addition of Dy³⁺ ions into the Fe₂O₃ system, the coercivity was decreased and the remanent magnetization was abruptly increased. The influence of dysprosium addition was also studied using electrochemical impedance spectroscopy. This study showed that in the presence of dysprosium ion, the charge transfer resistant increased in the electrochemical process.