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

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).

Download Full-text

Dielectric and ac conductivity of ilmenite-type CdTiO3 ceramic

Mediterranean Journal of Chemistry ◽

10.13171/10.13171/mjc8319052407rb ◽

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>

Download Full-text

AC conductivity and dielectric relaxation of Se80−xTe20Bix (x=6, 12) glasses

Physics and Chemistry of Glasses European Journal of Glass Science and Technology Part B ◽

10.13036/17533562.60.6.014 ◽

2019 ◽

Vol 60 (6) ◽

pp. 222-230

Author(s):

Deepika Deepika ◽

Hukum Singh

Keyword(s):

Dielectric Relaxation ◽

Ac Conductivity ◽

Lower Energy ◽

Dielectric Relaxation Time ◽

Frequency Exponent ◽

Dielectric Parameters ◽

Cbh Model ◽

Increase With Increase ◽

Different Temperatures ◽

Frequency Temperature

The present paper reports the ac conductivity and dielectric relaxation of Se80−xTe20Bix (x=6, 12) glasses at various temperatures and frequencies. It was found that ac conductivity increases on increase of frequency, temperature as well as Bi content. The increase in conductivity is due to the formation of lower energy Se–Bi and Te–Bi bonds which takes the system to a stable lower energy configuration. The values of frequency exponent (s) were calculated and it was found that samples obey CBH model of conduction. Density of states (N(Ef)) near the fermi level were calculated at different temperatures and it was found that addition of Bi increases the number of localised states in the tails which leads to increase in ac conductivity. Further, it was found that dielectric parameters increase with increase in temperature. However, a decrease in both dielectric constant (ε′) and dielectric loss ((ε″) was observed with increase in frequency. Beside this, dielectric relaxation time (τ) and activation energy of relaxation (∆Eτ) were also determined for both the samples under study and was found to be lower for Se68Te20Bi12 glass.

Download Full-text

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

Surface Review and Letters ◽

10.1142/s0218625x09013293 ◽

2009 ◽

Vol 16 (05) ◽

pp. 723-729 ◽

Cited By ~ 6

Author(s):

D. NITHYAPRAKASH ◽

B. PUNITHAVENI ◽

J. CHANDRASEKARAN

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Ac Conductivity ◽

Thermal Evaporation ◽

Frequency Range ◽

X Ray Diffraction ◽

Cbh Model ◽

X Ray ◽

Correlated Barrier Hopping ◽

Tan Δ

Thin films of In2Se3 were prepared by thermal evaporation. X-ray diffraction indicated that the as-grown films were amorphous in nature and became polycrystalline γ-In2Se3 films after annealing. The ac conductivity and dielectric properties of In2Se3 films have been investigated in the frequency range 100 Hz–100 kHz. The ac conductivity σ ac is found to be proportional to ωn where n < 1. The temperature dependence of both ac conductivity and the parameter n is reasonably well interpreted by the correlated barrier hopping (CBH) model. The values of dielectric constant ε and loss tangent tan δ were found to increase with frequency and temperature. The ac conductivity of the films was found to be hopping mechanism. In I–V characteristic for different field and temperature were studied and it has been found that the conduction process is Poole–Frenkel type.

Download Full-text

Dielectric and ac conductivity of ilmenite-type CdTiO3 ceramic

Mediterranean Journal of Chemistry ◽

10.13171/mjc8319052407rb ◽

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

Download Full-text

Conduction Mechanism by Using CBH Model in Fe3+ and Mn3+ Ion Modified Pb(Zr0.65−xAxTi0.35)O3 (A = Mn3+/Fe3+) Ceramics

Journal of Materials ◽

10.1155/2013/802123 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10

Author(s):

Niranjan Sahu ◽

S. Panigrahi ◽

Manoranjan Kar

Keyword(s):

Ac Conductivity ◽

Conduction Mechanism ◽

Rietveld Method ◽

Compositional Analysis ◽

Energy Dispersive Spectrum ◽

Ion Concentration ◽

Present Sample ◽

Cbh Model ◽

Dielectric Constant And Loss ◽

Xrd Patterns

Polycrystalline samples of manganese and iron substituted lead zirconium titanate (PZT) with general formula Pb(Zr0.65−xAxTi0.35)O3 (A = Mn3+ and Fe3+) ceramics have been synthesized by high temperature solid state reaction technique. X-ray diffraction (XRD) patterns were recorded at room temperature to study the crystal structure. All the patterns could be refined by employing the Rietveld method to R3c space group with rhombohedral symmetry. Microstructural properties of the materials were analyzed by scanning electron microscope (SEM), and compositional analysis was carried out by energy dispersive spectrum (EDS) measurements. All the materials exhibit ferroelectric to paraelectric transition. The variation of dielectric constant and loss tangent with temperature and frequency is investigated. The decrease of activation energy and increases of AC conductivity with the Fe3+ or Mn3+ ion concentration have been observed. The AC conductivity has been analyzed by the power law. The frequency exponent with the function of temperature has been analyzed by assuming that the AC conduction mechanism is the correlated barrier hopping (CBH) model. The conduction in the present sample is found to be of bipolaron type for Mn3+ ion-doped sample. However, the conduction mechanism could not be explained by CBH model for Fe3+ ion-doped sample.

Download Full-text

On the AC-conduction mechanism in Se-Te-Pb amorphous chalcogenide system: A detailed study through frequency-dependent imaginary part of AC conductivity

10.1063/5.0001285 ◽

2020 ◽

Author(s):

Anjali ◽

Balbir Singh Patial ◽

Nagesh Thakur

Keyword(s):

Imaginary Part ◽

Ac Conductivity ◽

Conduction Mechanism ◽

Frequency Dependent ◽

Amorphous Chalcogenide ◽

System A ◽

Ac Conduction

Download Full-text

Dielectric Studies on Alkali Borate Glasses Mixed with Iron Oxide

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.207.69 ◽

2013 ◽

Vol 207 ◽

pp. 69-96 ◽

Cited By ~ 1

Author(s):

T. Satyanarayana ◽

K. Srinivasa Rao ◽

N.T.V. Naga Lakshmi ◽

G. Nagarjuna

Keyword(s):

Dielectric Properties ◽

Borate Glasses ◽

X Ray Diffraction ◽

Melt Quenching ◽

X Ray ◽

Wide Range ◽

Alkali Oxides ◽

Alkali Borate Glasses ◽

Tan Δ ◽

Ac Conduction

Glass system of composition Li2O-Na2O-B2O3: Fe2O3with replacing alkali oxides one by another have been prepared via melt quenching. Further, the samples were characterized by X-ray diffraction. XRD studies have indicated that the prepared samples were amorphous in nature. Dielectric properties (constant ε , loss tan δ, a.c. conductivity σacover a wide range of frequency and temperature) of these glasses have also been explored. The activation energy for ac conduction is estimated to be the lowest for glass F25and the highest for glass F0. Finally the study on dielectric properties indicated that the ac conduction is predominantly ionic in nature in the samples containing high content of Li2O.Keywords:Borate glasses; dielectric properties; alkali effect

Download Full-text

Influence of BaO Doping on the Structural, ac Conductivity, and Dielectric Properties of BiFeO3 Multiferroic Nanoparticles

10.21203/rs.3.rs-204688/v1 ◽

2021 ◽

Author(s):

M. S. Ayoub ◽

Ibrahim Morad ◽

H. Elhosiny Ali ◽

M. M. Mostafa ◽

M. M. El–Desoky

Keyword(s):

Curie Temperature ◽

Ac Conductivity ◽

Conduction Mechanism ◽

Fourier Transforms ◽

Information Storage ◽

X Ray Diffraction ◽

Cbh Model ◽

Storage Devices ◽

Electrical Conductivities ◽

Xrd Patterns

Abstract The Bi1 − xBaxFeO3 (BiBaFeO3) multiferroic nanoparticles with different Ba molar concentrations were fabricated in reliance on the solid-state reaction technique. Nanostructures of the prepared samples were confirmed by X-ray diffraction (XRD) together with Fourier transforms infrared (FTIR) spectroscopy, whereas the ac conductivity, dielectric and ferroelectric features were examined depending on the RLC Bridge, and Sawyer–Tower circuit. XRD patterns displayed the creation of rhombohedral–hexagonal single-phase of BiBaFeO3. The formation of BiBaFeO3 multiferroic nanoparticles was confirmed by FTIR spectra. Curie temperature (TC) was observed around 1121–1189 K. Ferroelectric polarization was enhanced with remnant polarization of 88.8 µC/cm2 by Ba2+ ions substitution at x = 0.15 mol%. Besides, ac electrical conductivities as a function of frequency as well as temperature were reported for all BiBaFeO3 multiferroic nanoparticles, which exhibit a strong frequency dependence with conduction mechanism is the correlated barrier hopping (CBH) model. The obtained high polarization and Curie temperature enhance their use in information storage devices.

Download Full-text