Synthesis, Electrical and Magnetic Properties of Pr-Substituted Mn Ferrites for High-Frequency Applications

A series of spinel ferrites, MnPr (y) Fe2-y O-4 (y = 0.0, 0.025, 0.05, 0.075, 0.10), has been synthesized by the sol-gel autocombustion method. The structural properties of the prepared sintered powder were characterized by x-ray diffraction and then by using scanning electron microscopy. X-ray diffraction analysis shows that there is only spinel phase at low concentrations of praseodymium ions, while at high concentrations the prepared spinel ferrites have an ortho-ferrites phase along the spinel phase. The electrical and magnetic properties were investigated by the two-point probe method and a vibrating sample magnetometer respectively. Electrical measurements demonstrate that Bond length, resistivity and activation energy increase with the praseodymium substitution, while direct current electrical resistivity decreases with the increase of temperature, showing the semiconductor nature of the synthesized spinel ferrites. The saturation magnetization, remanence and coercivity (H-c) decrease with the increase of praseodymium contents. The anisotropic constant was observed to exhibit a similar behavior as coercivity. Soft magnetic behavior was observed for all the synthesized samples due to lower values of coercivity, up to a few hundreds. The above-mentioned parameters suggest that the synthesized samples are favorable for high frequency applications.