Improved dielectric, conductivity and magnetic properties of erbium doped α-Fe₂O₃ nanoparticles

This work demonstrates the synthesis of erbium (Er³⁺) ion doped ⍺-Fe₂O₃ nanoparticles through sol–gel method. The synthesized nanoparticles were thoroughly characterized by various analytical techniques such as XRD, FESEM and EDS, which confirmed that the prepared nanoparticles belong to hexagonal crystal structure with R-3c space group and are well crystalline and highly dense. The as synthesized nanoparticles were studied for dielectric, conductivity and magnetic properties. From dielectric studies, an increase in dielectric constant was observed with the increase in temperature and decrease in frequency. With Er³⁺ ion doping, a considerable increase in dielectric constant was observed for all doping concentrations. The temperature dependent dc conductivity follows Motts law thereby confirming variable range hopping mechanism in these systems. The room temperature magnetization was observed to increase significantly by incorporating Er³⁺ ions into ⍺-Fe₂O₃ lattice. In addition, an exciting result of this study was that the Er³⁺ ion doped ⍺-Fe₂O₃ nanoparticles saturate at low applied field of around 10 kOe compared to pure ⍺-Fe₂O₃ system which does not saturate up to the maximum applied field of 20 kOe. Attaining high saturation magnetization at low applied magnetic field in Er³⁺ ion doped ⍺-Fe₂O₃ system could provide a novel platform for medical applications.