scholarly journals Immittance Studies of Bi6Fe2Ti3O18 Ceramics

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5286 ◽  
Author(s):  
Agata Lisińska-Czekaj ◽  
Dionizy Czekaj ◽  
Barbara Garbarz-Glos ◽  
Wojciech Bąk
Keyword(s):  
Activation Energy ◽  
Electric Modulus ◽  
Complex Impedance ◽  
Dc Conductivity ◽  
Modulus Function ◽  
Conductivity Relaxation ◽  
Frequency Range ◽  
A Value ◽  
Polycrystalline Ceramics ◽  
Electric Behavior

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.

Synthesis and Electrical Properties of SmBi5Fe2Ti3O18

1998 ◽  
Vol 12 (10) ◽  
pp. 371-381 ◽  
Author(s):  
N. V. Prasad ◽  
G. Prasad ◽  
T. Bhimasankaram ◽  
S. V. Suryanarayana ◽  
G. S. Kumar
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Electrical Impedance ◽  
Complex Impedance ◽  
Dc Conductivity ◽  
Frequency Range ◽  
Oxide Compound ◽  
Sintering Method

SmBi 5 Fe 2 Ti 3 O 18, a five layered bismuth oxide compound is synthesized using a solid-state double sintering method. DC conductivity, impedance, and AC conductivity are studied in the temperature range 30–500°C and frequency range 1 kHz–1 MHz. Complex impedance plots are used to separate grain and grain boundary contributions to electrical impedance. Activation energy for DC conductivity was found to be around 1.0 eV. The results are analyzed to understand the conductivity mechanism.

Dielectric Relaxation Spectroscopic Measurements on a Novel Electroactive Polyimide

1999 ◽  
Vol 600 ◽  
Author(s):  
Saadi Abdul Jawad ◽  
Abdalla Alnajjar ◽  
Mamoun M. Bader
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Electric Modulus ◽  
High Thermal Stability ◽  
Side Chain ◽  
Electrical Behavior ◽  
Frequency Range ◽  
Kcal Mole ◽  
Electro Optic

AbstractAC electrical behavior of a novel aromatic electro-optic polyimide was investigated in the temperature range 25 °C to 300 °C and a frequency range from 1 Hz to 106 Hz. Three electrical quantities: impedance, permittivity and electric modulus are reported. The dependence of imaginary and real components of these quantities on temperature and frequency are discussed. The experimental results show that the polymer has high thermal stability below 200 °C, where the resistivity, dielectric constant and permittivity are nearly temperature-independent indicating highly rigid structure. Above this temperature, however, a well-defined broad peak corresponding to a relaxation process was observed for which the activation energy was calculated to be 8.5 Kcal/mole. This relaxation is associated with a restricted local rotational motion of the side chain chromophore.

scholarly journals Study of complex impedance spectroscopic properties of La 0.7− x Dy x Sr 0.3 MnO 3 perovskite oxides

2018 ◽  
Vol 5 (11) ◽  
pp. 172201 ◽  
Author(s):  
I. Sfifir Debbebi ◽  
S. Megdiche-Borchani ◽  
W. Cheikhrouhou-Koubaa ◽  
A. Cheikhrouhou
Keyword(s):  
Activation Energy ◽  
Sol Gel ◽  
Complex Impedance ◽  
Spectroscopic Properties ◽  
Perovskite Oxides ◽  
Perovskite Oxide ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Dc Conductivities ◽  
X Ray

The dysprosium perovskite La 0.7− x Dy x Sr 0.3 MnO 3 ( x = 0.00 [LSMO] and 0.03 [LDSMO]) compounds were prepared by the sol–gel reaction and characterized by the X-ray diffraction technique. The electrical conductivity and modulus characteristics of the system have been investigated in the temperature and the frequency range 311–356 K and 209–5 × 10 7 Hz, respectively, by means of impedance spectroscopy. The ac and dc conductivities were studied to explore the mechanisms of conduction of LSMO and LDSMO. The insertion of a small amount of Dy 3+ in the La-site of LSMO perovskite oxide increases the value of the activation energy from 0.2106 to 0.5357 eV and enhances electrical resistivity values for almost two orders of magnitude.

Molecular relaxation in Chitosan films in GHz frequency range

2014 ◽  
Vol 1613 ◽  
pp. 83-88
Author(s):  
Siva Kumar-Krishnan ◽  
Evgen Prokhorov ◽  
Gabriel Luna-Barcenas
Keyword(s):  
Activation Energy ◽  
Low Frequency ◽  
Bound Water ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Temperature Range ◽  
A Value ◽  
Chitosan Films ◽  
First Time

ABSTRACTThe molecular relaxations behavior of chitosan (CS) films in the wide frequency range of 0.1-3x109 Hz (by using three different impedance analyzers) have been investigated in the temperature range of -100C to 120°C using Dielectric Spectroscopy (DS). Additionally to the low frequency molecular relaxations such as α and β relaxations, for the first time, high frequency (1-3 GHz) relaxation process has been observed in the chitosan films. This relaxation exhibits Arrhenius-type dependence in the temperature range of -100 C to 54°C with negative activation energy -2.7 kJ/mol. At temperatures above 54°C, the activation energy changes from -2.7 kJ/mol to +4.4 kJ/mol. Upon cooling, the activation energy becomes negative again with a value of -1.2 kJ/mol. The bound water between chitosan molecules strongly modifies molecular motion and the relaxation spectrum, giving rise to a new relaxation at the frequency at ca. 1 GHz. In situ FTIR analysis has shown that this relaxation related to the changes in vibration of the –OH, NH and –CO functional groups.

scholarly journals Electrical Property Analysis of Textured Ferroelectric Polycrystalline Antimony Sulfoiodide Using Complex Impedance Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2579
Author(s):  
Anna Starczewska ◽  
Bartłomiej Toroń ◽  
Piotr Szperlich ◽  
Marian Nowak
Keyword(s):  
Electrical Property ◽  
Impedance Spectroscopy ◽  
Electric Modulus ◽  
Complex Impedance ◽  
Complex Impedance Spectroscopy ◽  
Frequency Range ◽  
Ac Impedance Spectroscopy ◽  
Antimony Sulfoiodide ◽  
First Time ◽  
Internal Domain

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.

AC Conductivity and Mechanism of Conduction Study of ?-Sr2P2O7 Using Impedance Spectroscopy

2014 ◽  
Vol 4 (1) ◽  
pp. 433-448
Author(s):  
Makram Megdiche ◽  
Mohamed Gargouri
Keyword(s):  
Activation Energy ◽  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Frequency Range ◽  
Solid State Reaction Technique ◽  
Modulus Analysis ◽  
Power Law Exponent ◽  
Large Polaron ◽  
Olpt Model ◽  
The Difference

The ceramic sample Sr2P2O7 was prepared by a solid-state reaction technique at high temperature. Electrical properties and modulus analysis were studied using complex impedance spectroscopy in the frequency range 200 Hz–5 MHz and temperature range 602-714 K. The difference of the value of activation energy for the bulk obtained from analysis of equivalent circuit (0.81 eV) and modulus relaxation (0.69 eV) confirms that the transport is not due from a simple hopping mechanism. The average of the power law exponent s is reasonably interpreted by the overlapping large polaron tunneling (OLPT) model. The mechanism of conduction is probably due from the displacements of the Sr2+ ion in the tunnel-type cavities along the b axis.

scholarly journals Influence of Bismuth Content on Complex Immittance Characteristics of Pressureless Sintered BiNbO4 Ceramics

2014 ◽  
Vol 59 (1) ◽  
pp. 225-229 ◽  
Author(s):  
D. Czekaj ◽  
A. Lisinńska-Czekaj ◽  
M. Adamczyk
Keyword(s):  
Complex Impedance ◽  
Conductivity Relaxation ◽  
Frequency Range ◽  
Stoichiometric Mixture ◽  
Reaction Route ◽  
Impedance Data ◽  
Measuring Frequency ◽  
Resistive Component ◽  
The One ◽  
Bi2o3 Content

Abstract Goal of the present research was to study immittance properties of BiNbO4 ceramics fabricated by the solid state reaction route followed by pressureless sintering. Four sets of samples were examined, namely the one fabricated from the stoichiometric mixture of oxides, viz. Bi2O3 and Nb2O5 as well as the ones with an excess of 3%, 5% and 10% by mole of Bi2O3. The immittance properties were studied by impedance spectroscopy. Measurements were carried out within the frequency range ν =20Hz-1MHz and temperature range T =RT-550°C. The Kramers-Kronig data validation test was employed in the impedance data analysis. It was found that complex impedance first increases with an increase in Bi2O3 content and decreases for 10mol% excess of Bi2O3. Two relaxation phenomena manifested themselves at elevated temperature (T>267°C) within the measuring frequency range. The conductivity relaxation phenomenon (M″(ν) spectra) took place at higher frequency than the phenomenon with dominant resistive component (Z″(ν) spectra).

Conductivity, Dielectric and Modulus study of NH4PF6 based Zwitterionic polymer electrolyte

2020 ◽  
Vol 13 ◽  
Author(s):  
Manindra Kumar ◽  
Neelabh Srivastava
Keyword(s):  
Polymer Electrolyte ◽  
Power Law ◽  
Loss Tangent ◽  
Electric Modulus ◽  
Relaxation Behavior ◽  
Conductivity Data ◽  
Frequency Range ◽  
Zwitterionic Polymer ◽  
Power Law Equation ◽  
Jonscher’S Power Law

Background and Objective: Zwitterionic polymer electrolyte has been successfully synthesized using NH4PF6 salt. The conductivity of the synthesized polymer membrane is found to be of the order of 10-3Scm-1. Dielectric and Modulus properties of the polymer electrolyte have also been studied which showed well relaxation peaks with both temperature and salt concentrations. Result: This is well depicted with the loss tangent curve. Debye type relaxation behavior has observed from the electric modulus. Conclusion: Frequency dependent conductivity data (fitted with Jonscher's power law equation) confirmed the presence of NCL/SLPL type behavior in the studied frequency range.

Anderson-Stuart Model to Analyze AC and DC Conductivity of Lithium Zinc-Silicate Glass / Glass-Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 919-924
Author(s):  
M.S. Jogad ◽  
V.K. Shrikhande ◽  
A.H. Dyama ◽  
L.A. Udachan ◽  
Govind P. Kothiyal
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Low Frequency ◽  
Frequency Region ◽  
Dc Conductivity ◽  
Frequency Range ◽  
High Frequency Region ◽  
Dc Conductivities ◽  
Conductivity Variation ◽  
Different Temperatures

AC and DC conductivities have been measured by using the real (e¢) and imaginary (e¢¢) parts of the dielectric constant data of glass and glass-ceramics (GC) at different temperatures in the rage 297-642K and in the frequency range 100 Hz to 10 MHz. Using Anderson –Stuart model, we have calculated the activation energy, which is observed to be lower than that of the DC conductivity. The analysis for glass/glass-ceramics indicates that the conductivity variation with frequency exhibits an initial linear region followed by nonlinear region with a maximum in the high-frequency region. The observed frequency dependence of ionic conductivity has been analyzed within the extended Anderson–Stuart model considering both the electrostatic and elastic strain terms. In glass/glassceramic the calculations based on the Anderson-Stuart model agree with the experimental observations in the low frequency region but at higher frequencies there is departure from measured data.

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