Complex impedance and electric modulus studies of magnetic ceramic Ni0.27Cu0.10Zn0.63Fe2O4

Abstract

Abstract:The electrical properties of Ni 0.27 Cu 0.10 Zn 0.63 Fe 2 O 4 (NCZF) prepared from auto combustion synthesis of ferrite powders have been studied by impedance and modulus spectroscopy. We studied frequency and temperature dependencies of impedance and electric modulus of NCZF in a wide frequency range (20 Hz-5 MHz) at different measuring temperatures SM T (30-225 ℃). The complex impedance spectra clearly showed both grain and grain boundary effects on the electrical properties. The observed impedance spectra indicated that the magnitude of grain boundary resistance gb R becomes more prominent compared to grain resistance b R at room temperature, and with the increase in SM T , gb R decreases faster than the intrinsic b R . The frequency response of the imaginary part of impedance showed relaxation behavior at every SM T , and the relaxation frequency variation with SM T appeared to be of Arrhenius nature and the activation energy has been estimated to be 0.37 eV. A complex modulus spectrum was used to understand the mechanism of the electrical transport process, which indicated that a non-Debye type of conductivity relaxation characterizes this material.

Dielectric studies and AC conductivity of piezoelectric barium titanate ceramic polymer composites

“…Complex impedance spectroscopy was used to analyze the electrical properties of composites with conducting electrodes in a frequency range of 100 Hz to 1 MHz at room temperature. 19 Complex impedance and electric modulus analyses were done using these formulae:…”

Deficient or excessive CuO‐TiO2 phase influence on dielectric properties of CaCu3Ti4O12 ceramics

“…On the other hand, the curves with larger values of M′′ present a slight tendency for the region of high frequency (>10 5 Hz) and are related to the system that has lower dielectric constant, in this case, corresponds to the CT/excessive ceramics, thus indicating an electric response associated with grains. Moreover, above 1 MHz it is noticed the considerable increase in M′′ for all CC X T Y O ceramics, this dielectric behavior at the high frequency region should be due to bulk contribution, it can be attributed to small dielectric constant of grains, being harmful to high ε′ of the ceramics at high frequencies.…”

“…The peaks are more pronounced for the CT/deficient CC X T Y O ceramics, which as previously seen present the highest electrical relaxations. All these experimental results reveal that ε′′ at low frequency should be due to interface polarization from grain boundaries, while the dielectric relaxation peaks at high frequency region can be associated to the bulk or grain effects, attributed to phenomena associated with accumulation of space charges or point defects …”

“…For a more detailed understanding of the dielectric behavior of the CCTO ceramics, the electric modulus ( M* ) was used, which is related as M* = 1/ ε * (ω) = j( ω C 0 )Z* = M′ + jM′′, where ( M′ ) and ( M′′ ) are the real and imaginary components of electric modulus, respectively . The use of the electric modulus spectrum allows the visualization of the distribution of the relaxation frequencies .…”

Development of High-Performance Bismuth Sulfide Nanobelts Humidity Sensor and Effect of Humid Environment on its Transport Properties

“…So, the electrode effect is eliminated in the material. 46 With an increase in RH, M ′ curves shift toward higher frequencies, indicating the increase in DC conductivity. 47 Figure 6c shows the imaginary part of modulus ( M ″) vs log f .…”