Electrical properties of Y-type hexaferrite

The polycrystalline sample of Ba2Mg2Fe[Formula: see text]O[Formula: see text] was prepared by solid-state reaction technique. Room-temperature X-ray diffraction (XRD) has confirmed the formation of rhombohedral structure. The electrical properties of the sample were studied in wide ranges of temperatures and frequencies. The impedance analysis indicates the presence of bulk effect. The bulk resistance of the material decreases with rise in temperature and exhibits NTCR behavior. This compound also exhibits the temperature-dependent non-Debye type of relaxation phenomena. The presence of non-Debye type of relaxation has been confirmed by the complex impedance analysis. The variation of DC conductivity (bulk) with temperature demonstrates that the compound exhibits Arrhenius type of electrical conductivity. The activation energy of the compound is found to be 0.55[Formula: see text]eV in high-temperature region.

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

Journal of Advanced Dielectrics ◽

10.1142/s2010135x15500071 ◽

2015 ◽

Vol 05 (01) ◽

pp. 1550007 ◽

Cited By ~ 2

Author(s):

M. Saidi ◽

A. Chaouchi ◽

S. D'Astorg ◽

M. Rguiti ◽

C. Courtois

Keyword(s):

Complex Impedance ◽

Negative Temperature ◽

Impedance Analysis ◽

Xrd Analysis ◽

Ac Impedance ◽

Nyquist Plot ◽

X Ray Diffraction ◽

Complex Impedance Analysis ◽

Lead Free Ceramics ◽

Different Temperatures

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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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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ELECTRICAL PROPERTIES OF LiCoVO4 CERAMICS

International Journal of Modern Physics B ◽

10.1142/s0217979211100540 ◽

2011 ◽

Vol 25 (12) ◽

pp. 1619-1628 ◽

Cited By ~ 2

Author(s):

MOTI RAM

Keyword(s):

Electrical Properties ◽

Complex Modulus ◽

Cell Structure ◽

Complex Impedance ◽

Lattice Parameter ◽

Conductivity Relaxation ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Compound Formation ◽

C Complex

Solution-based chemical method was used to prepare the compound LiCoVO 4. Compound formation was checked by X-ray diffraction (XRD) study and it revealed a cubic unit cell structure with lattice parameter: a = 8.2840 (3) Å. Complex impedance result shows bulk contribution to electrical properties up to 225°C, grain boundary effects for all T ≥ 250° C , and evidence of temperature-dependent electrical relaxation phenomena in the material. The values of activation energy were determined from the Arrhenius plot of DC conductivity versus 103/T and were equal to ~0.09 eV at 50–200°C and ~0.48 eV at 200–350°C. Complex modulus study indicates non-Debye type (polydispersive) conductivity relaxation in the compound.

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