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

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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Electrical properties of Y-type hexaferrite

Journal of Advanced Dielectrics ◽

10.1142/s2010135x18500224 ◽

2018 ◽

Vol 08 (03) ◽

pp. 1850022 ◽

Cited By ~ 1

Author(s):

Bibhuti B. Sahu ◽

S. K. Patri ◽

Banarji Behera ◽

B. Maharana

Keyword(s):

Electrical Properties ◽

Complex Impedance ◽

Polycrystalline Sample ◽

Impedance Analysis ◽

Rhombohedral Structure ◽

X Ray Diffraction ◽

Temperature Dependent ◽

Solid State Reaction Technique ◽

Complex Impedance Analysis ◽

Bulk Effect

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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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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Investigation on microstructure and electrical properties of Bi doping Ca3Co4O9 nanoparticles synthesized by sol-gel process

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i2.29.13121 ◽

2018 ◽

Vol 7 (2.29) ◽

pp. 31

Author(s):

Mohammed M A ◽

Izman Sudin ◽

Alias Mohd Noor ◽

Srithar Rajoo ◽

Uday M B ◽

...

Keyword(s):

Electrical Resistivity ◽

Electrical Properties ◽

Sol Gel ◽

Combustion Method ◽

Variable Pressure ◽

X Ray Diffraction ◽

Sol Gel Process ◽

Gel Combustion ◽

Bi Doping ◽

Increasing Temperature

In this study, nanoparticles of Bi doped Ca3-xCo4O9 [Ca3-xBixCo4O9 where x=0, 0.2, 0.4 and 0.6] were prepared by sol gel combustion method. The phase structures and microstructures of Bi doped Ca3-xCo4O9 powders preparation were investigated. The microstructural observations of different Bi doped Ca3-xCo4O9 powders were evaluated using X-ray diffraction analysis (XRD) and Variable Pressure Scanning Electron Microscope (VPSEM). The bulk Ca3-xBixCo4O9 samples were fabricated using uniaxial cold pressing technique. Electrical resistivity of bulk Ca3-xBixCo4O9 samples with different doping was measured using four-probe method from 300 to 700°K. The electrical resistivity was found to decrease with increasing temperature for the bulk Ca3-xBixCo4O9 samples. The electrical properties of Ca3-xBixCo4O9 are non-monotonic functions of x.

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Investigation on electrical conductivity and dielectric property of La0.8Pb0.2(Fe,Ti)0.5O3 ceramic nanoparticles

Journal of Advanced Dielectrics ◽

10.1142/s2010135x19500292 ◽

2019 ◽

Vol 09 (04) ◽

pp. 1950029

Author(s):

D. Triyono ◽

Y. Supriyadi ◽

H. Laysandra

Keyword(s):

Small Polaron ◽

Sol Gel ◽

Complex Impedance ◽

Impedance Analysis ◽

Ceramic Materials ◽

Ceramic Nanoparticles ◽

Complex Impedance Analysis ◽

Giant Dielectric ◽

Semiconductor Behavior ◽

Giant Dielectric Constant

The modification of the structure lanthanum orthoferrites (LaFeO[Formula: see text] to obtain ceramic materials with enhanced structural, optical, and electrical properties constitutes an active area of research. The preparation of La[Formula: see text]Pb[Formula: see text](Fe, Ti)[Formula: see text]O3 (LPFTO) ceramic nanoparticles by following a cation substitution approach from LaFeO3 using sol–gel and sintering methods is described. The electrical and dielectric properties of the obtained material are investigated. The contribution of grain and grain boundary in the conduction mechanism is demonstrated by complex impedance analysis. The LPFTO ceramic nanoparticles exhibit a giant dielectric constant of the order of 108. The conductivity analysis suggests the occurrence of thermally activated semiconductor behavior. Moreover, the ferromagnetic–paramagnetic semiconductor transition temperature is observed at 385[Formula: see text]K. The ac conductivity behavior satisfies the nonoverlapping small-polaron tunneling (NSPT) model.

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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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