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

2015 ◽  
Vol 4 (3) ◽  
pp. 217-225 ◽  
Author(s):  
M. Belal Hossen ◽  
A. K. M. Akther Hossain
2012 ◽  
Vol 02 (03) ◽  
pp. 1250008 ◽  
Author(s):  
B. PARIJA ◽  
S. PANIGRAHI ◽  
T. BADAPANDA ◽  
T. P. SINHA

We report the temperature and frequency dependence impedance spectroscopy of (1 - x) ( Bi 0.5 Na 0.5) TiO 3-x BaTiO 3 (abbreviated as BNT–BT) ceramics with 0 ≤ x ≤ 0.07 prepared by conventional solid-state route. X-ray diffraction analysis indicated that a solid solution is formed when BaTiO3 diffuses into the (Bi0.5Na0.5)TiO3 lattice and a morphotropic phase boundary between rhombohedral and tetragonal locates at x = 0.07. The microstructure indicated that the grain size reduces and the shape changes from rectangular to quasi-spherical with increase in BaTiO3 content. Complex Impedance Spectroscopy analysis suggested the presence of temperature-dependent relaxation process in the materials. The modulus mechanism indicated the non-Debye type of conductivity relaxation in the materials, which is supported by impedance data. The activation energies have been calculated from impedance, electric modulus studies and dc conductivity which suggests that the conductions are ionic in nature. The activation energy increases with increase of BT content up to x = 0.05 and decreases at x = 0.07 which also indicates the presence of morphotropic phase boundary at x = 0.07.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5286 ◽  
Author(s):  
Agata Lisińska-Czekaj ◽  
Dionizy Czekaj ◽  
Barbara Garbarz-Glos ◽  
Wojciech Bąk

Results of studies focusing on the electric behavior of Bi6Fe2Ti3O18 (BFTO) ceramics are reported. BFTO ceramics were fabricated by solid state reaction methods. The simple oxides Bi2O3, TiO2, and Fe2O3 were used as starting materials. Immittance spectroscopy was chosen as a method to characterize electric and dielectric properties of polycrystalline ceramics. The experimental data were measured in the frequency range Δν = (10−1–107) Hz and the temperature range ΔT = (−120–200) °C. Analysis of immittance data was performed in terms of complex impedance, electric modulus function, and conductivity. The activation energy corresponding to a non-Debye type of relaxation was found to be EA = 0.573 eV, whereas the activation energy of conductivity relaxation frequency was found to be EA = 0.570 eV. An assumption of a hopping conductivity mechanism for BFTO ceramics was studied by ‘universal’ Jonscher’s law. A value of the exponents was found to be within the “Jonscher’s range” (0.54 ≤ n ≤ 0.72). The dc-conductivity was extracted from the measurements. Activation energy for dc-conductivity was calculated to be EDC = 0.78 eV, whereas the dc hopping activation energy was found to be EH = 0.63 eV. The obtained results were discussed in terms of the jump relaxation model.


2013 ◽  
Vol 547 ◽  
pp. 83-89
Author(s):  
Sangeeta Singh ◽  
Parveen Kumar ◽  
Chandra Prakash ◽  
J.K. Juneja

Single phase Ba0.8Pb0.2TiO3 (BPT) with improved dielectric and ferroelectric properties was synthesized by Mechano-Chemical Activation (MCA). It is also interesting to investigate the change in different electrical parameters of the sample synthesized by MCA. In the present work, we are reporting the Complex Impedance spectroscopy (CIS) of BPT ceramics synthesized by MCA. Complex quantities like electric modulus (M*) and impedance (Z*) were calculated from measured dielectric constant (ε) and tanδ measured as a function of frequency (70Hz-1MHz) upto 500oC. To understand the relaxation behavior, real and imaginary parts of M* and Z* were plotted as a function of frequency at different temperatures. Typical Cole-Cole plots of Z′ and Z″ indicate the contribution from both grain and grain boundary to the relaxation mechanism.


2008 ◽  
Vol 22 (14) ◽  
pp. 2321-2331 ◽  
Author(s):  
K. P. CHANDRA ◽  
R. N. GUPTA ◽  
K. PRASAD

The electrical properties of alizarin doped anthraquinone were investigated using a complex impedance spectroscopy technique. Dielectric study revealed a phase transition from the semiconducting to the conducting state at 53°C. The dielectric relaxation was found to be of non-Debye type. Evidence of temperature-dependent electrical relaxation phenomena as well as a positive temperature coefficient of conductivity character were observed in the sample. The frequency dependence of AC conductivity data followed a power law. Electric modulus as well as AC conductivity analyses indicated the possibility of a hopping mechanism for electrical conduction in the system. The activation energy and minimum hopping distance were estimated from the AC conductivity data.


2020 ◽  
Vol 17 (3) ◽  
pp. 276-280
Author(s):  
R. Swarnalatha ◽  
A. Sadananda Chary ◽  
Venkata Ramana Jeedi ◽  
Yalla Mallaiah ◽  
S. Narender Reddy

Polymer solid electrolytes PMMA(80,70,60,50): PC(10,20,30,40):PVP(10):LiClO4(5) were synthesized according to stoichiometric ratios using solution cast method. FTIR study confirms the good complexation among the constituent materials in the polymers matrix. Complex impedance and electric modulus studies are carried out and explained. From cole-cole plots, maximum decrement of resistance is observed at a threshold ratio 70Wt% PMMA: 20Wt% PC: 10Wt% PVP: 5Wt% LiClO4 and this could be due to the high mobility of the Li+ ion in the polymer network due to the plasticizer. The plasticizer plays an important role in decreasing the viscosity of the system, which in turn favors the mobility of segmental motion of polymer network and fast ion motion in the polymer. Real and Imaginary electric modulus spectra show the presence of relaxation peaks and confirm that the polymer solid electrolyte is an ionic conductor.


Open Physics ◽  
2014 ◽  
Vol 12 (12) ◽  
Author(s):  
Ajay Behera ◽  
Nilaya Mohanty ◽  
Santosh Satpathy ◽  
Banarji Behera ◽  
Pratibindhya Nayak

Abstract0.5BiNdxFe1−x O 3 − 0.5PbTiO3 (BNxF1−x − PT)(x = 0.05, 0.10, 0.15, 0.20) composites were successfully synthesized by a solid state reaction technique. At room temperature, X-ray diffraction shows tetragonal structure for all concentrations of Nd doped 0.5BiFeO3 − 0.5PbTiO3 composites. The nature of Nyquist plot confirms the presence of bulk effects only for BNxF1−x − PT (x = 0.05, 0.10, 0.15, 0.20) composites. The bulk resistance is found to decreases with the increasing temperature as well as Nd concentration and exhibits a typical negative temperature coefficient of resistance (NTCR) behavior. Both the complex impedance and modulus studies have suggested the presence of non-Debye type of relaxation in the composites. Conductivity spectra reveal the presence of hopping mechanism in the electrical transport process of the composites. The activation energy calculated from impedance plot of the composite decreases with increasing Ndx concentration and found to be 0.89, 0.76, 0.71 and 0.70 eV for x=0.05, 0.10, 0.15 and 0.20 respectively.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2579
Author(s):  
Anna Starczewska ◽  
Bartłomiej Toroń ◽  
Piotr Szperlich ◽  
Marian Nowak

Antimony sulfoiodide (SbSI) is a ferroelectric semiconductor with many interesting physical properties (optical, photoconductive, ferroelectric, piezoelectric, etc.). The electrical properties of textured polycrystalline SbSI obtained by the rapid cooling of a melted mass in liquid nitrogen are presented in this work using ac impedance spectroscopy over a wide temperature range (275–500 K) in the frequency range of 1 Hz to 100 kHz. Detailed studies of the impedance Z*(ω), conductivity σ*(ω), electric modulus M*(ω), and dielectric permittivity ε*(ω) of this material were performed using complex impedance spectroscopy for the first time. This study showed that the impedance and related parameters are strongly dependent on temperature. The internal domain structure and the presence of grain boundaries in textured polycrystalline SbSI explain the obtained results.


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