Electrical and magnetic properties of nano-sized Eu doped barium hexaferrites

Magnetic and electrical response of nano-sized europium doped M-type barium hexaferrites have been reported in the study. The nano-sized material was synthesized through hydrothermal technique and the doping concentration of Eu was kept at 0, 0.02, 0.04, 0.08 and 0.10. Effects of doping on structural, magnetic and electric properties have been investigated in detail. The structural analysis through XRD and FTIR confirms the formation of single-phase M-type hexaferrites with hexagonal structure. The morphological and size analysis was carried out using SEM and TEM. The electrical measurements were performed in the frequency range 40 Hz-100 MHz. Different electrical response of grain interface and grain core was observed for pure and Eu doped samples. The ac conductivity of all the samples show linear relation with frequency of applied field following the Jonscher's power law and the overall conductivity decreases with dopant concentration. In the Nyquist plot, two semicircles are observed for all the samples. Z-View software is used to simulate the experimental data and to separate out the resistance and capacitance of electrode, grain interface and grain core. It is found that the resistance of the electrode and grain interface decreases with doping of Eu. The increase in dielectric constant at low frequency shows the enhanced conductive behaviour, however at high frequency the dielectric constant merges due to the release of space charges. Furthermore, the magnetic analysis revealed that saturation magnetization increases from 30.49 to 54.27 emu/g and coercivity from 3.03 to 8.73 kOe with doping of Eu.