Dielectric, ferroelectrics properties and impedance spectroscopy analysis of the [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3-based lead-free ceramics

Polycrystalline of [( Na 0.535 K 0.480)0.966 Li 0.058] (Nb 0.90 Ta 0.10) O 3 samples were prepared using the high-temperature solid-state reaction technique. X-ray diffraction (XRD) analysis indicates the formation of a single-phase with orthorhombic structure. AC impedance plots were used as tool to analyze the electrical behavior of the sample as a function of frequency at different temperatures. The AC impedance studies revealed the presence of grain effect, from 425°C onwards. Complex impedance analysis indicated non-Debye type dielectric relaxation. The Nyquist plot showed the negative temperature coefficient of resistance (NTCR) characteristic of NKLNT. The AC conductivity results were used to correlate with the barrier hopping (CBH) model to evaluate the binding energy (Wm), the minimum hopping distance (R min ), the density of states at Fermi level (N(Ef)), and the activation energy of the compound.

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Relaxation mechanism and conductivity studies of lead-free ceramics: Fe1/2(NaLi)1/4TiO3

Modern Physics Letters B ◽

10.1142/s0217984920500815 ◽

2020 ◽

Vol 34 (06) ◽

pp. 2050081

Author(s):

Subrat Kumar Barik ◽

A. R. Atique Ulla

Keyword(s):

Complex Impedance ◽

Negative Temperature ◽

Relaxation Mechanism ◽

Lead Free ◽

X Ray Diffraction ◽

Prepared Sample ◽

Lead Free Ceramics ◽

Wide Range ◽

Different Temperatures ◽

Energy Formula

A single-phase lead-free ferroelectric compound, Fe[Formula: see text](NaLi)[Formula: see text]TiO3, is found at room temperature. The solid state reaction technique helps to process the sample at the calcination and sintering temperatures of 900 and 950[Formula: see text][Formula: see text]C for 4 h respectively. The desired phase and crystal structure formation of the prepared sample are confirmed by analysis of X-ray diffraction (XRD) data and are found to be in orthorhombic structure. The correlation among phase formation and physical properties has been established by using complex impedance spectroscopy (CIS) method over a wide range of frequencies (from 100 Hz to 1 MHz) and different temperatures (25–280[Formula: see text][Formula: see text]C). The overlap depressed semicircular arcs represent the association of grain and grain boundary effects in the material. Activation energy [Formula: see text] is noted to be 1 eV for the prepared sample. The frequency dependent ac conductivity is followed by Jonscher’s universal power law. DC conductivity versus temperature graph also indicates the negative temperature coefficient of resistance (NTCR) behavior of the material.

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An intensive study on the AC impedance mechanism of (AgPO3)1-x(Ag2SO4)x ionic glass systems under various conditions

World Journal of Engineering ◽

10.1108/wje-01-2019-0001 ◽

2019 ◽

Vol 16 (4) ◽

pp. 477-486

Author(s):

Atif Alkhazali ◽

Morad Etier ◽

Mohammad Aljarrah ◽

Akram Alsukker ◽

Fathy Salman

Keyword(s):

Complex Impedance ◽

Entropy Change ◽

Impedance Analysis ◽

Cole Plot ◽

X Ray Diffraction ◽

Content Type ◽

Activation Free Energy ◽

Complex Impedance Analysis ◽

Different Temperatures ◽

Increasing Temperature

Purpose The purpose of this study is to investigate the effect of the considerable Ag2SO4 content on the electrical and dielectric properties of (AgPO3)1−x(Ag2SO4)x ion glass system as well as to extract thermodynamic parameters. Design/methodology/approach Glass samples of (AgPO3)1-x(Ag2SO4)x with different mole ratios of Ag2SO4 [x = 0.00, 0.10,0.15,0.20 and 0.25] have been synthesized and used. X-ray diffraction and differential thermal analysis were used to investigate structural and thermal properties, and then the electrical characterizations of the bulk glasses were performed in different frequency and temperature range. Findings For different ratios of Ag2SO4 on AgPO3, the bulk conductivity is enhanced with increasing the amount of Ag2SO4 until the composition of x = 0.20, after which the conductivity decreases. The general behavior of both ε’ and ε” decreases with increasing frequency and increases with increasing temperature. Complex impedance analysis studied by Z‘−Z’ and Cole–Cole plot at different temperatures revealed that bulk resistance decreases with temperature. Originality/value The calculated values of activation free energy, enthalpy and entropy change for different compositions of (AgPO3)1-x(Ag2SO4)x showed an increase in activation energy and enthalpy when Ag2SO4 ratio is increased in (AgPO3)1-x(Ag2SO4)x composition up to 20%, and then there is a decrease in their values at x = 25%, which may be explained based on non-bridging oxygen.

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COMPLEX IMPEDANCE SPECTROSCOPY ON ZnO-B2O3 DOPED (Ba, Sr)TiO3 CERAMICS

Surface Review and Letters ◽

10.1142/s0218625x10013606 ◽

2010 ◽

Vol 17 (01) ◽

pp. 27-32 ◽

Cited By ~ 2

Author(s):

SANG-HO MOON ◽

YONG-SU HAM ◽

JUNG-HYUK KOH

Keyword(s):

Impedance Spectroscopy ◽

Complex Impedance ◽

Negative Temperature ◽

Nyquist Plot ◽

X Ray Diffraction ◽

X Ray ◽

Different Temperatures ◽

Bst Ceramics ◽

Grain Growth Behavior ◽

Microscopy Images

BST ceramics with doping of 1, 3, and 5 wt.% ZnBO were prepared by the conventional mixed oxide method and sintered at 1100°. X-ray diffraction analyses were carried out to verify the structural properties. 1, 3, and 5 wt.% ZnBO doped BST ceramics were crystallized with weak tetragonal structure at 1100°C. The grain growth behavior and shapes were investigated by scanning electron microscopy images. The electrical properties of 1, 3, and 5 wt.% ZnBO doped BST ceramics were investigated by impedance spectroscopy at the different temperatures (350, 375, and 400°C). Impedance spectroscopy data presented in Nyquist plot show the existence of both grain and grain boundary effects in all specimens. 1, 3, and 5 wt.% ZnBO doped BST ceramics showed negative temperature coefficient of resistance (NTCR). Also, the capacitances and resistances of grains and grain boundaries for 1, 3, and 5 wt.% doped BST ceramics were simulated through equivalent circuit with the parallelly connected capacitors and resistors. The capacitance and resistance were decreased when temperature and ZnBO dopants were increased.

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Structural and Impedance Analysis of 0.7Pb(Mg1/3Nb2/3)O3- 0.3PbTiO3 Ceramic

Micro and Nanosystems ◽

10.2174/1876402913666210929125515 ◽

2021 ◽

Vol 13 ◽

Author(s):

Jayanta Kumar Mishra ◽

Khusboo Agrawal ◽

Banarji Behera

Keyword(s):

Electrical Properties ◽

Short Range ◽

Complex Impedance ◽

Relaxation Effect ◽

Impedance Analysis ◽

Xrd Analysis ◽

Nyquist Plot ◽

Space Group ◽

Complex Impedance Analysis ◽

Mobility Of Charge Carriers

Background: Since (1-x)[Pb(Mg1/3Nb2/3)O3]-(x)PbTiO3 (PMN-PT) ceramic has high dielectric constant and piezoelectric coefficient, it has been widely investigated for profound applications in electro-optical devices, sensors, multilayer capacitors and actuators. Objectives: The aim is to study the structural and electrical properties of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) ceramic to understand the biphasic structural nature using Rietveld Refinement. Also, it characterises on the basis of electrical properties such as impedance and modulus to understand the relaxation process, type of conduction process as well as the role of grain and grain boundary resistance in the material. Methods: 0.7PMN-0.3PT is synthesised by mixed oxide method using PbO, MgO, Nb2O5 and TiO2 as precursor materials. Results: The XRD data reveals the biphasic structure of tetragonal phase with the space group of P4mm and monoclinic phase with the space group of Pm. The complex impedance analysis clearly represents the effect of grain on the overall resistance and departs from normal Debye type behaviour. Also, the resistance is found to decrease with temperature, thereby confirming the semiconducting nature of the sample. The presence of long as well as short-range mobility of charge carriers is confirmed from the modulus and impedance analysis. The influence of long-range motion is observed at high temperature and of short-range motion at low temperatures. Conclusion: XRD analysis confirmed the biphasic structure of M+T phase. The frequency-dependent modulus and impedance spectroscopy show the presence of a relaxation effect in the ceramic which is found to increase with temperature. The Nyquist plot shows that the resistance is decreased with temperature, thereby confirming the NTCR behaviour in the studied sample.

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Grain boundary effects in NTC-PTC composite thermistor materials

Journal of Materials Research ◽

10.1557/jmr.1999.0019 ◽

1999 ◽

Vol 14 (1) ◽

pp. 120-123 ◽

Cited By ~ 10

Author(s):

D. J. Wang ◽

J. Qiu ◽

Y. C. Guo ◽

Z. L. Gui ◽

L. T. Li

Keyword(s):

Energy Level ◽

Grain Boundary ◽

Boundary Effect ◽

Complex Impedance ◽

Negative Temperature ◽

Impedance Analysis ◽

Composite Effect ◽

Complex Impedance Analysis ◽

Temperature Coefficient Of Resistivity ◽

Grain Boundary Effect

Yttrium-doped (Sr0.45Pb0.55)TiO3 ceramics have been studied by complex impedance analysis. As a sort of NTC-PTC composite thermistor, it exhibited a significantly large negative temperature coefficient of resistivity below Tc in addition to the ordinary PTC characteristics above Tc. It is found that the NTC effect in NTC-PTC materials was not originated from the deep energy level of donor (bulk behavior), but from the electrical behavior of the grain boundary. Therefore, the NTC-PTC composite effect was assumed to be a grain boundary effect, and yttrium was a donor at shallow energy level. The NTC-PTC ceramics were grain boundary controlled materials.

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The effects of calcination and doping on structural and dielectric properties of CaCu3-xCoxTi4O12 ceramic

Mediterranean Journal of Chemistry ◽

10.13171/10.13171/mjc8319052011nh ◽

2019 ◽

Vol 8 (3) ◽

pp. 234

Author(s):

Nasr Hadi ◽

Tajdine Lamcharfi ◽

Farid Abdi ◽

Nor-Said Echtoui ◽

Ahmed Harrach ◽

...

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Complex Impedance ◽

Impedance Analysis ◽

Xrd Analysis ◽

Secondary Phases ◽

Solid State Method ◽

Complex Impedance Analysis ◽

Oxide Powders ◽

Increasing Temperature

The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu3-xCoxTi4O12 (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 0C for 8h were investigated. The ceramic samples are prepared by the conventional solid-state method using high purity oxide powders, and they are calcined at 850 °C, 950 °C and 1050 0C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 0C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 0C was observed. Scanning electron microscopy (SEM) investigation showed an increase in grain size with increasing of Co content and calcining temperature. Dielectric measurements indicated that the dielectric constant of the pure CCTO calcined at 1050 0C/4h has a low value in the frequency range of 1kHz up to 1MHz, whereas the substitution of Co up to x = 0.10 into CCTO caused a huge increase in the dielectric constant value of the calcined samples which is equal to 153419 and 18957 at 950 °C and 1050 0C respectively. The complex impedance analysis of all samples shows a decrease in resistance with an increasing temperature, which suggests a semiconductor nature of the samples.

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Free Volumes Associated with Sintering in Gadolinium Doped Ceria Solid Solutions

Journal of Nanomaterials ◽

10.1155/2010/935146 ◽

2010 ◽

Vol 2010 ◽

pp. 1-5 ◽

Cited By ~ 4

Author(s):

Tomomi Kosaka ◽

Kiminori Sato

Keyword(s):

Positron Lifetime ◽

Complex Impedance ◽

Impedance Measurement ◽

Impedance Analysis ◽

Doped Ceria ◽

X Ray Diffraction ◽

Complex Impedance Analysis ◽

Ceria Solid Solutions ◽

Positron Lifetime Spectroscopy ◽

Gadolinium Doped Ceria

Gadolinium-doped ceria (GDC) solid solution prepared by the oxalate coprecipitation method is investigated by X-ray diffraction (XRD), complex impedance analysis, and positron lifetime spectroscopy. XRD reveals an expansion of GDC lattice constant by doping gadolinium into a ceria host crystal, in agreement with an oxygen vacancy model. The ionic conductivity of GDC measured at 773 K in air is two orders of magnitude higher than that of undoped ceria. Positron lifetime spectroscopy reveals the presence of vacancy-sized free volumes and nanovoids in interfaces among crystallites. It is found that the vacancy-sized free volumes shrink with increasing sintering temperatures. In the present paper, recent advances in the studies of GDC by XRD, complex impedance measurement, and positron lifetime spectroscopy are reviewed to gain an insight into the sintering mechanism.

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Synthesis, Structure and Electrical Properties of Pr-Doped Apatite-Type Lanthanum Silicates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1094.155 ◽

2015 ◽

Vol 1094 ◽

pp. 155-159

Author(s):

Li Peng Tian ◽

Zhi Hua Ren

Keyword(s):

Electrical Properties ◽

Sol Gel ◽

Complex Impedance ◽

Impedance Analysis ◽

Total Conductivity ◽

X Ray Diffraction ◽

Complex Impedance Analysis ◽

Sol Gel Process ◽

Lanthanum Silicates ◽

Apatite Type

Apatite-type lanthanum silicates doped with Pr3+ at the La site, La10-xPrxSi6O27 (x = 0, 1, 2, 3, 4, 4.5), were synthesized via sol-gel process. Thermal behavior of the dried gel of La10-xPrxSi6O27 sample was studied using TG/DTA. X-ray diffraction, SEM and complex impedance analysis were used to investigate the microstructure and electrical properties of La10-xPrxSi6O27 ceramics. The XRD results indicated the maximum doping quantity of Pr3+ is x = 4.5. Lanthanum silicates doped with Pr3+ cations have a higher total conductivity than that of undoped lanthanum silicates. The enhanced total conductivity depends on the improved density of La10-xPrxSi6O27 (x = 0, 1, 2, 3, 4, 4.5). At 973K, the highest total conductivity is 1.36×10-3S.cm-1 for La9PrSi6O27 ceramic.

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Impedance spectroscopy studies on lead free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 ceramics

Processing and Application of Ceramics ◽

10.2298/pac1204201c ◽

2012 ◽

Vol 6 (4) ◽

pp. 201-207 ◽

Cited By ~ 13

Author(s):

Ahcène Chaouchi ◽

Sadia Kennour

Keyword(s):

High Temperature ◽

Impedance Spectroscopy ◽

Grain Boundary ◽

Boundary Effect ◽

Complex Impedance ◽

Negative Temperature ◽

Polycrystalline Sample ◽

Impedance Analysis ◽

Wide Frequency Range ◽

Nyquist Plot

The AC complex impedance spectroscopy technique has been used to obtain the electrical parameters of polycrystalline sample of (Ba0.85Ca0.15) (Ti0.9Zr0.1)O3 in a wide frequency range at different temperatures. This sample was prepared by a high temperature solid-state reaction technique and single phase formation was confirmed by X-ray diffraction technique. This study was carried out by the means of simultaneous analysis of impedance, modulus, and electrical conductivity. The Cole-Cole (Nyquist) plots suggest that the grains and grain boundaries are responsible in the conduction mechanism of the material at high temperature. The Cole- Cole (Nyquist) plot studies revealed the presence of grain and grain boundary effect at 485 ?C. On the other hand, it showed only the presence of grain boundary component of the resistivity at 535 ?C. Complex impedance analysis indicated the presence of non-Debye type dielectric relaxation. The bulk resistance of the material decreases with rise in temperature similar to a semiconductor, and the Cole-Cole (Nyquist) plot showed the negative temperature coefficient of resistance (NTCR) character of (Ba0.85Ca0.15 )(Ti0.9Zr0.1 )O3. The value of activation energy is found to be 0.7433 eV, which suggests that the conduction may be the result of defect and charge carriers present in the materials.

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Effect of barium doping on electrical and electromechanical properties of (1-x)(Na0.5Bi0.5)TiO3-xBaTiO3

Mediterranean Journal of Chemistry ◽

10.13171/mjc8319050908mm ◽

2019 ◽

Vol 8 (3) ◽

pp. 198-208

Author(s):

Mohammed Mesrar ◽

Tajdine Lamcharfi ◽

Nor-Said Echatoui ◽

Farid Abdi ◽

Fatima Zahra Ahjyaje ◽

...

Keyword(s):

Dielectric Constant ◽

Complex Impedance ◽

Impedance Analysis ◽

Xrd Analysis ◽

Secondary Phases ◽

Solid State Method ◽

Complex Impedance Analysis ◽

Oxide Powders ◽

Increasing Temperature ◽

A Site

The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu3-xCoxTi4O12 (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 0C for 8h were investigated. The ceramic samples are prepared by the conventional solid-state method using high purity oxide powders, and they are calcined at 850 °C, 950 °C and 1050 0C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 0C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 0C was observed. Scanning electron microscopy (SEM) investigation showed an increase in grain size with increasing of Co content and calcining temperature. Dielectric measurements indicated that the dielectric constant of the pure CCTO calcined at 1050 0C/4h has a low value in the frequency range of 1kHz up to 1MHz, whereas the substitution of Co up to x = 0.10 into CCTO caused a huge increase in the dielectric constant value of the calcined samples which is equal to 153419 and 18957 at 950 °C and 1050 0C respectively. The complex impedance analysis of all samples shows a decrease in resistance with an increasing temperature, which suggests a semiconductor nature of the samples

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