Electrical transport properties of Mn–Ni–Zn ferrite using complex impedance spectroscopy

Abstract

Polycrystalline Mn 0.45 Ni 0.05 Zn 0.50 Fe 2 O 4 was prepared by a standard solid state reaction technique. We report the electrical properties of this ferrite using ac impedance spectroscopy as a function of frequency (20 Hz-10 MHz) at different temperatures (50-350 • C). X-ray diffraction patterns reveal the formation of cubic spinel structure. Complex impedance analysis has been used to separate the grain and grain boundary resistance of this ferrite. The variation of grain and grain boundary conductivities with temperature confirms semiconducting behavior. The dielectric permittivity shows dielectric dispersion at lower frequency and reveals that it has almost the same value on the high-frequency side. The non-coincidence of peaks corresponding to modulus and impedance indicates deviation from Debye-type relaxation. A similar value of activation energy is obtained from impedance and modulus spectra, indicating that charge carriers overcome the same energy barrier during relaxation. Electron hopping is responsible for ac conduction in this ferrite. The electron hopping shifts toward higher frequency with increasing temperature, below which the conductivity is frequency independent. The frequency-independent ac conductivity has been observed at and above 300 • C in the frequency range 20 Hz-1 MHz. This frequency-independent ac conductivity is due to the long-range movement of the mobile charge carriers.

Detailed investigation of the structural and electrical properties of ZnO/Fe3O4 nanocomposites

“…The converging of the ¢ Z values at higher frequencies for all temperatures can be attributed to the non-appearance of space charge in the grain boundary area and as a result an increase in ac conductivity [88]. The behavior of Z′ in the current samples for both lower and higher frequencies agree well with previously published results [89][90][91][92].…”

Temperature-dependent dielectric properties of p-n heterojunction diodes based on hydrothermally synthesized ZnO nanostructures

“…It is also seen that the M′ curves tend to saturate as they go to sufficiently high frequencies. In addition, M′ values indicate that the dispersion increases with increasing temperature, thus attributing the transition of mobility of charge carriers from short-distance conduction at low temperatures to long-distance conduction at high temperatures [47]. The low values of M″ in the M″ frequency-dependent graph in figure 3(b) indicate that the electrode effects make a negligible contribution.…”

Decolonization of MB Dye (C16H18CIN3S) under the Natural Light Using Pristine and Zn−Y Substituted CoFe2O4 as a Catalyst

“…Additionally, the conduction process is caused by the abundance of Fe 2+ ions at the octahedral site. The Arrhenius relation [38] equation (17) was used to calculate the DC‐electrical resistivity of the Zn−Y 3+ replaced CFMNPs and the unaltered CFMNPs. $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr \rho ={{\rm \rho }}_{0}\times {\rm exp}\left({{\Delta {E}_{a}}\over{kT}}\right)\hfill\cr}}$$$ …”

“…Additionally, the conduction process is caused by the abundance of Fe 2 + ions at the octahedral site. The Arrhenius relation [38] equation ( 17) was used to calculate the DC-electrical resistivity of the ZnÀ Y 3 + replaced CFMNPs and the unaltered CFMNPs.…”