Electrical Transport of Mn-Zn-Ti Ferrite with Fe-Poor Composition

摘要

The real parts of the complex permittivity and complex impedance spectra of Mn-Zn-Ti ferrite with Fe-poor composition (FPF:Fe_2O_3 less than 50 mol percent) were measured. The relaxation time was estimated by numerical fitting of the permittivity spectra data. The relaxation time of FPF was about 10~(-5)-10~(-6) s, because dielectric relaxation occurred below 1 MHz. The resistance of the grains is separated from that of the grain boundary in the complex impedance spectra. As a result, it was found that the relaxation time is proportional to the resistance of the grains. It is reasonable to suppose that the relaxation time is related to the electrical mobility. The temperature dependences of the real parts of the complex permittivity and the complex impedance spectra of the same sample were measured. The activation energy of the resistances of the grains was a little larger than that of the relaxation times.