Study of Mn doped multiferroic DyFeO3 ceramics

Structural, Raman, room temperature and temperature dependent leakage current density, dielectric, magnetization and room temperature Mossbauer studies of Mn doped DyFeO3 (i.e., DyFe1-xMnxO3; x=0 to 0.5) polycrystalline materials prepared through sol-gel route are reported in this paper. From Rietveld refinement of x-ray diffraction (XRD) patterns it is found that all the samples are formed in single phase without any detectable impurity. The Raman modes with doping are consistent with literature of such doped orthoferrites. From the room temperature (RT) leakage current density (J-E) measurements, it is observed that leakage current density increases with Mn doping concentration, which is explained in terms of microstructure. The leakage current density is found to decrease with the decrease of temperature in each sample as observed from low temperature leakage current density (J-E) measurements. Further, activation energy is calculated from the temperature dependent J-E data. The dielectric loss data is observed to exhibit frequency dependence and the activation energy obtained indicate the contribution from space charges. From temperature dependent magnetization data, it is found that with the increase of Mn content, the spin reorientation (SR) transition temperature (T-SR) moves towards higher temperature. From M-H curves at 10 K and 300 K with different Mn doping concentrations, it is found that saturation Magnetization (M-s) decreases with increase of Mn doping. Room temperature Mossbauer data shows the presence of Fe3+ state and the gradual decrease of internal hyperfine filed with increase of Mn content.