scholarly journals Dielectric and ac conductivity of ilmenite-type CdTiO3 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 255-260
Author(s):  
Radouane Bahloul ◽  
Salaeddine Sayouri ◽  
TajEddine Lamcharfi
Keyword(s):  
Loss Tangent ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Sol Gel ◽  
Complex Impedance ◽  
Powder Sample ◽  
Hopping Conduction ◽  
Bulk Resistance ◽  
Tan Δ

Cadmium titanate CdTiO3 powder sample was prepared using the sol-gel route and calcined at 900°C. The dependence of the permittivity, loss tangent (tan δ) on the temperature in the range 40–600°C, and frequency in the range 103–2.106 Hz for the pure hexagonal ilmenite is reported. The ln(σac) versus T plots suggest that the conduction mechanism is of ionic hopping nature. The evolution of ln(σac) as a function of frequency suggests that the ionic hopping conduction decreases with the rise in temperature. The complex impedance plots revealed two depressed semicircular arcs indicating the bulk and interface contributions. The bulk resistance was found to increase with a decrease in temperature exhibiting typical semiconductor-like behavior

scholarly journals Dielectric and ac conductivity of ilmenite-type CdTiO3 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 255
Author(s):  
Radouane Bahloul ◽  
Salaeddine Sayouri ◽  
TajEddine Lamcharfi
Keyword(s):  
Loss Tangent ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Sol Gel ◽  
Complex Impedance ◽  
Powder Sample ◽  
Hopping Conduction ◽  
Bulk Resistance ◽  
Tan Δ

<p class="Abstracttitle">Cadmium titanate CdTiO3 powder sample was prepared using the sol-gel route and calcined at 900°C. The dependence of the permittivity, loss tangent (tan δ) on the temperature in the range 40–600°C, and frequency in the range 103–2.106 Hz for the pure hexagonal ilmenite is reported. The ln(σac) versus T plots suggest that the conduction mechanism is of ionic hopping nature. The evolution of ln(σac) as a function of frequency suggests that the ionic hopping conduction decreases with the rise in temperature. The complex impedance plots revealed two depressed semicircular arcs indicating the bulk and interface contributions. The bulk resistance was found to increase with a decrease in temperature exhibiting typical semiconductor-like behavior.</p>

AC CONDUCTION PHENOMENON OF Li2O–WO3–B2O3 GLASSES DOPED WITH V2O5

2013 ◽  
Vol 06 (03) ◽  
pp. 1350032 ◽  
Author(s):  
LINGANABOINA SRINIVASA RAO ◽  
NALLURI VEERAIAH ◽  
TUMU VENKATAPPA RAO
Keyword(s):  
High Temperatures ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Glass Composition ◽  
Melt Quenching ◽  
Frequency Exponent ◽  
Spreading Factor ◽  
Cbh Model ◽  
Tan Δ ◽  
Ac Conduction

The glass composition 40 Li 2 O –5 WO 3–(55−x) B 2 O 3: x V 2 O 5 for x = 0.2, 0.4, 0.6 and 0.8 is chosen for the present study. The glass samples were synthesized by conventional melt-quenching technique. The dielectric properties such as constant (ε′), loss (tan δ) and ac conductivity (σac) are carried out as a function of temperature (30–270°C) and frequency (102–105 Hz). The glass sample (at x = 0.6) exhibited highest ac conductivity (σac) and spreading factor (β) among all the samples. All glasses exhibited mixed conduction (both electronic and ionic) at high temperatures. The frequency exponent s denotes the ac conduction mechanism is associated with both QMT model (at low temperatures) and CBH model (at high temperatures).

scholarly journals Effect of Microwave Sintering on Electrical Properties of Sr-deficient and Bi-rich Strontium Bismuth Niobate (Sr0.8Bi2.2Nb2O9) Ferroelectric Ceramic

2016 ◽  
Vol 1 (1) ◽  
pp. 35-45 ◽  
Author(s):  
RAJVEER SINGH ◽  
Vandna Luthra ◽  
Ram Pal Tandon
Keyword(s):  
Conduction Mechanism ◽  
Microwave Sintering ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Ferroelectric Ceramic ◽  
Relaxation Mechanism ◽  
Bulk Resistance ◽  
Conventional Solid State Reaction ◽  
Debye Relaxation ◽  
Bismuth Niobate

Nonstoichiometric strontium bismuth niobate (Sr0.8Bi2.2Nb2O9: SBN) ceramic was prepared using conventional solid-state reaction and microwave sintering methods. Complex impedance spectroscopy (CIS) has been used to investigate the intra and intergranular contribution to the impedance SBN ceramics as a function of temperature and frequency. Complex impedance Cole‑Cole plots were used to interpret the relaxation mechanism in SBN ceramic which showed a non-Debye relaxation. The grain and grain boundary contribution to conductivity have been estimated from the Cole‑Cole plots. The bulk (grain) resistance of both samples was found to decrease with rise in temperature indicating negative temperature coefficient of resistance (NTCR) type behavior like that of semiconductors. The microwave sintered SBN was found to have low value of bulk resistance indicating more increase in conductivity as compared to conventionally sintered SBN. The temperature dependence of the relaxation time was found to obey the Arrhenius law. Studies of electrical modulus show the presence of hoping conduction mechanism in SBN.

scholarly journals Dielectric Relaxation and Hopping Conduction in La2NiO4+δ

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Woo-Hwan Jung
Keyword(s):  
Dielectric Relaxation ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Complex Impedance ◽  
Relaxation Property ◽  
Relaxation Mechanism ◽  
Angular Frequency ◽  
Limited Temperature ◽  
Electrical Data ◽  
Bulk Effect

An ac conductivity as well as dielectric relaxation property of La2NiO4.1 is reported in the temperature range of 77 K–130 K and in the frequency range of 20 Hz–1 MHz. Complex impedance plane plots show that the relaxation (conduction) mechanism in this material is purely a bulk effect arising from the semiconductive grain. The relaxation mechanism has been discussed in the frame of electric modulus spectra. The scaling behavior of the modulus suggests that the relaxation mechanism describes the same mechanism at various temperatures. The logarithmic angular frequency dependence of the loss peak is found to obey the Arrhenius law with the activation energy of ~0.09 eV. The frequency-dependent electrical data are also analyzed in the frame of ac conductivity formalism. The ac conductivity has been found to follow a power-law behavior at a limited temperature and frequency region where Anderson localization plays a significant role in the transport mechanism for La2NiO4.1.

Preparation and High Temperature Thermoelectric Properties of [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 Compound

2007 ◽  
Vol 336-338 ◽  
pp. 805-808 ◽  
Author(s):  
Xiao Ya Li ◽  
Yun Yu ◽  
Dong Li Wang ◽  
Li Dong Chen
Keyword(s):  
High Temperature ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Conduction Mechanism ◽  
Sol Gel ◽  
Hopping Conduction ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Thermoelectric Energy ◽  
Spark Plasma

[Ca2(Co0.65Cu0.35)2O4]0.624CoO2 polycrystalline samples were prepared using sol-gel method followed by spark plasma sintering. Thermoelectric properties of the samples were examined from room temperature to 1000K. The temperature dependence of electrical conductivity shows that the hole hopping conduction mechanism is dominant for the samples. The activation energy of hopping conduction is 0.11 eV. At the temperature of about 1000K, the electrical resistivity is 7.1m cm, the thermopower is 160 μVK-1, the thermal conductivtity is 2.94Wm-1K-1 and dimensionless figure of merit reaches 0.12. These results indicate [Ca2(Co0.65Cu0.35)2O4]0.624CoO2 is a potential material for high temperature thermoelectric energy conversion.

scholarly journals Complex Impedance, Dielectric Properties and Electrical Conduction Mechanism of LaBa0.5Ag0.5FeMnO6 Double Perovskite Oxides

2021 ◽  
Author(s):  
Kais Iben Nassar ◽  
Nizar Rammeh ◽  
Sílvia Soreto Teixeira ◽  
Manuel Pedro F. Graça
Keyword(s):  
Conduction Mechanism ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Double Perovskite ◽  
Perovskite Oxide ◽  
Impedance Function ◽  
Cubic System ◽  
Constant Phase Elements ◽  
Frequency Curves

Abstract The double perovskite oxide with formula LaBa0.5Ag0.5FeMnO6 was prepared by the sol-gel method. The structural analysis at room temperature indicated that this sample is single phase and crystallize in the cubic system with the Pm-3m space group. The complex impedance spectroscopy has been measured in the range of temperature, 200–340 K, and frequency, 100 Hz–1MHz, respectively. Dielectric measurements by analysis of the impedance function, Z" as a function of Z' versus frequency curves, were mounted to an equivalent circuit consisting of series of combinations of resistor, capacity and constant phase elements. The study of ac conductivity as a function of frequency has been interpreted using the Joncher's law and determines the activation energy. The modulus analysis was also performed indicating the presence of a relaxation process accompanied by a conduction phenomenon.

scholarly journals Complex impedance, dielectric properties and electrical conduction mechanism of La0.5Ba0.5FeO3−δ perovskite oxides

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76659-76665 ◽  
Author(s):  
S. Nasri ◽  
A. L. Ben Hafsia ◽  
M. Tabellout ◽  
M. Megdiche
Keyword(s):  
Dielectric Properties ◽  
Electrical Conduction ◽  
Conduction Mechanism ◽  
Sol Gel ◽  
Complex Impedance ◽  
Perovskite Oxides ◽  
Gel Method ◽  
Sol Gel Method ◽  
Electrical Conduction Mechanism

The new perovskite compound La0.5Ba0.5FeO3−δ was prepared by the sol–gel method.

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

AC conductivity and conduction mechanism study of rubidium gadolinium diphosphate compound

2018 ◽  
Vol 93 (5) ◽  
pp. 603-610 ◽  
Author(s):  
Samia Mathlouthi ◽  
Abderrazek Oueslati ◽  
Bassem Louati
Keyword(s):  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Mechanism Study
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