Structural, magnetic and electrical properties of pure and Dy-doped Fe۲O۳ nanostructures synthesized using chemical thermal decomposition technique

Pure (S۱) and Dy۳+-doped α-Fe۲O۳ (S۲ and S۳) nanoparticles were prepared by a combustion synthesis method at ۷۰۰ ºC for ۸ h using Fe(acac)۳ (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 FullProf 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-Fe۲O۳ crystal structure (S۳). The results showed that the patterns had a main hexagonal structure with space group R . The cell parameters data, calculated by rietveld analysis, showed that the cell parameters were decreased with increasing the dopant (Dy۳+) amount in the α-Fe۲O۳ crystal structure. The average particles sizes estimated from TEM images for S۳ were about ۶۰ nm. Besides, the magnetic properties of S۱ and S۳ were measured by vibrating sample magnetometer (VSM). It was found that with the addition of Dy۳+ ions into the Fe۲O۳ 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.

Keywords:

Combustion synthesis , electrochemical impedance spectroscopy , Magnetic property , Nano-structure characterization , X-ray powder diffraction