Dispersion Spectra of Permeability and Permittivity for LiZnMn Ferrite Doped With ${\hbox {Bi}}_{2}{\hbox {O}}_{3}$

The effects of Bi 2 O 3 on dispersion spectra of permeability and permittivity for LiZnMn ferrite prepared by a conventional ceramic method were investigated. Optimum content of Bi 2 O 3 can obviously affect the permeability and permittivity of LiZnMn ferrite via promoting grain growth and densification. The permeability spectra of LiZnMn ferrite were resolved into two contribution components, domain wall movement and spin rotation magnetization. The fitting results manifest that, with Bi 2 O 3 concentration increasing, the major contribution to dynamic magnetization changes from spin rotation magnetization mechanism to domain wall movement, and the domain wall spectra change from resonance-type to relaxation-type, but the spin rotation spectra behave in the opposite way. Meanwhile, the mechanism of dielectric polarization and dielectric loss of the samples were discussed.