Rare earth substituted M-type lead hexaferrite: synthesis, electrical and magnetic properties

In this article, the synthesis and the electrical and magnetic characterization of the M-type lead hexaferrite were presented. Rare-earth substituted lead hexaferrite was synthesized by the traditional ceramic process. The final product was obtained by sintering the lead hexaferrite compact at 950 degrees C for 2 h. According to the XRD analysis, secondary phases did not appear in the patterns. The electrical polarization curve of the sample did not confirm the ferroelectric response. The dielectric constant vs. frequency indicated a reduction trend. As observed from the polarization curve, the polarization value changed between 0.8 and-0.8 mu C/cm2 under the voltage of 5.76 kV. The high symmetry of the crystal in this sample is proposed to be the origin of the absence of ferroelectric response. Vibrating sample magnetometer (VSM) measurements confirmed the ferrimagnetic behaviour for both RT and low temperature. The saturation magnetizations (Ms) were found to be 7.54-8.08 emu/g in the temperature range of 7-22 K and the highest coercivity value was found to be 1.2 kOe and this result depicts the magnetically soft nature and multi-domain structure. The results showed that the obtained lead hexaferrite sample has acceptable magnetic properties.