Magnetic and electric behavior of praseodymium substituted CuPryFe2-yO4 ferrites

Spinel ferrites with chemical formula CuPryFe2-yO4(y=0.0,0.02,0.04,0.06,0.08,0.10) were synthesized using sol-gel technique. The sintered powder characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and vibrating sample magnetometer (VSM). X-ray Diffraction analysis showed that the samples with concentration (y=0.0-0.06) have single spinel phase and the samples with concentration at y=0.08-0.10 have secondary phase (ortho ferrite phase) along spinel phase. The Lattice constant a increased with the substitution of Praseodymium (Pr) ions. The crystallite size calculated from Scherre's formula is found in the range of 53-37 nm. It is observed that DC resistivity and activation energy enhances with the substitution of Pr. The dc resistivity decreased with the increase in temperature. The conduction below Curie temperature (Tc) is due to hopping of electrons and holes, whereas, above Curie temperature it is due to polaron hopping. The decrease in Tc with increasing Pr constant may be due to the fact that Pr-Fe interactions on the B sites are weaker than Fe-Fe interaction. The saturation magnetization (Ms) and remanence (Mr) decreased where as coercivity (Hc) has been increased with the increase of Pr content. The measured parameters suggest that these materials are potential candidates for high frequency applications.