Complex permeability spectra of PbO and Ta2O5 added nanocrystalline MgCuZn ferrites

PbO and Ta2O5 added MgCuZn ferrites are prepared by the Microwave-Hydrothermal (M-H) processing. The nanocrystalline ferrites are sintered to a temperature of 900 °C/4 h. SEM pictures reveal that, the addition of PbO causes a small amount of grain growth, whereas the addition of Ta2O5 causes a fine-grained microstructure. The complex permeability spectra (µ⁎=μ′−iμ″) of the prepared samples were measured in the frequency range from 1 MHz to 1.8 GHz, the µ⁎ spectra are analyzed into two magnetization processes with focus on the particle size of ferrite samples. In addition to the spin rotation relaxation in 130-200 MHz, it is initially identified the contribution from reversible domain wall bowing rising at 6-40 MHz. The magnetic state of the ferrite is also influenced by the addition of PbO and Ta2O5. The spin rotation mechanism of the present ferrites is enhanced by the preparation of nanocrystalline samples.