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

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.

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

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.

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 Enhancement in DC Electrical Resistivity and Dielectric Behaviour of Ti4+ Doped CoFe2O4 NP’s for Nanoelectronics Application

2020 ◽  
Vol 9 (6) ◽  
pp. 257-262
Keyword(s):  
Cobalt Ferrite ◽  
Average Crystallite Size ◽  
Information Storage ◽  
Dielectric Behaviour ◽  
X Ray Diffraction ◽  
Dielectric Parameters ◽  
Phase Spinel ◽  
Vibrational Bands ◽  
Ft Ir ◽  
Xrd Patterns

Inverse spinel structured cobalt ferrite is one of the capable nominee for information storage and also in nanoelectronics devices. The present paper reports the rietveld refined structural, elastic, electrical and dielectric behaviour of titanium doped CoFe2O4 NP’s. The synthesis of Co1+xTixFe2-2xO4 (where, 0.0  x  0.5) nanoparticles was performed using self generated combustion technique. The prepared NP’s were characterized by X-ray diffraction technique (XRD) and Fourier transform infrared spectroscopy (FT-IR) technique to analyze the structural and elastic properties. The analysis of XRD patterns confirms the formation of single phase spinel cubic structure of all the prepared samples. The diffractograms obtained at room temperature were used for Rietveld refinement to determine the lattice constant, oxygen position, average crystallite size etc. parameters. The elastic modules were investigated through vibrational bands in FTIR spectra. The band positions in FT-IR spectra confirmed the octahedral [B] and tetrahedral (A) stretching which evident the ferrite skeleton. The plot of DC electrical resitivity with respect to temperature shows the semiconducting behaviour of the nanoparticles. The activation energy determined through resistivity plots, show decreasing nature with incrementing Ti4+ doping in cobalt ferrite. The dielectric parameters decreased exponentially with increasing frequency and with Ti doping.

TRANSPORT PROPERTIES OF THERMALLY EVAPORATED In2Se3 THIN FILMS

2009 ◽  
Vol 16 (05) ◽  
pp. 723-729 ◽  
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.

scholarly journals Structural properties and magnetic interactions in Al3+ and Cr3+ co-substituted CoFe2O4 ferrite

2010 ◽  
Vol 8 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Surendra More ◽  
Ram Kadam ◽  
Ankush Kadam ◽  
Dhanraj Mane ◽  
Govind Bichile
Keyword(s):  
Curie Temperature ◽  
Magnetic Interactions ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Cr Content ◽  
Phase Spinel ◽  
Cr Substitution ◽  
Xrd Patterns ◽  
Co Precipitation

AbstractA series of CoAlxCrxFe2−2xO4 systems (x = 0.1 to 0.5 in steps of x = 0.1) spinel ferrites have been synthesized successfully using wet chemical co-precipitation technique. The samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and magnetization measurements. The powder XRD patterns confirm the single phase spinel structure for the materials synthesized. X -ray diffraction measurements were performed to yield the lattice constant as function of the amount x corresponding to Al-Cr substitution. Lattice parameters, X-ray density, bulk density and particle size decrease whereas porosity increases with the increase in Al-Cr content, ‘x’. Infrared studies show two absorption bands at about 400 cm−1 and 600 cm−1 for octahedral and tetrahedral sites, respectively. Saturation magnetization decreases with the increase in Al-Cr content x. AC magnetic susceptibility measurements were carried out as a function of temperature to measure the Curie temperature, which was found to decrease with Al-Cr content x. The decrease of Curie temperature has been explained by A-B interaction.

STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF PET POLYMER FILMS MODIFIED BY LOW ENERGY Ar+ ION BEAMS

2018 ◽  
Vol 25 (03) ◽  
pp. 1850066 ◽  
Author(s):  
Y. H. A. FAWZY ◽  
H. M. ABDEL-HAMID ◽  
M. M. EL-OKR ◽  
A. ATTA
Keyword(s):  
Ion Irradiation ◽  
Carbon Cluster ◽  
Industrial Applications ◽  
Ion Beams ◽  
Ion Source ◽  
X Ray Diffraction ◽  
Electrical Conductivities ◽  
Xrd Patterns ◽  
Argon Ion ◽  
Pet Films

Polyethylene terephthalate (PET) films with thickness 40[Formula: see text][Formula: see text]m are irradiated with 3[Formula: see text]keV argon ion beams with different fluence ranging from [Formula: see text][Formula: see text]ions.cm[Formula: see text] to [Formula: see text][Formula: see text]ions.cm[Formula: see text] using locally designed broad ion source. The changes in the PET structure are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope (SEM) techniques. The XRD patterns show that the peak intensity decreases with irradiation and the particle size decreases from 65.75 Å for the un-irradiated to 52.80 Å after irradiation. The FTIR indicates partial decrease and reduction in the intensity of the bands due to the degradation of the polymer after ion irradiation. The optical energy band gap decreases from 3.14[Formula: see text]eV to 3.05[Formula: see text]eV and the number of carbon cluster increases from 119 to 126 after ion irradiation. The results show a slight increase in the electrical conductivities and the dielectric constant ([Formula: see text]). The results indicate the effectiveness of using PET films as capacitors and resistors in industrial applications.

AC CONDUCTIVITY AND DIELECTRIC STUDIES ON Sr0.6Na0.2Nd0.2Bi4Ti4O15 CERAMIC

2008 ◽  
Vol 22 (10) ◽  
pp. 775-783 ◽  
Author(s):  
RIZWANA ◽  
T. RADHA KRISHNA ◽  
P. SARAH
Keyword(s):  
Diffraction Data ◽  
Mixed Oxide ◽  
High Frequency ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Temperature Dependency ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures

Sr 0.6 Na 0.2 Nd 0.2 Bi 4 Ti 4 O 15 ceramic is prepared by mixed oxide method. Lattice parameters for this ceramic are calculated from the X-ray diffraction data. Dielectric studies as a function of temperature and frequency are done. To understand the process of conduction involved in the material prepared, frequency and temperature dependency of AC conductivity studies are carried out. The two-term power relation is used to characterize the frequency dependence of AC conductivity. The parameters s1, s2 (low and high frequency slopes) are calculated from the AC conductivity plots at different temperatures to get more information about the conduction mechanism. Conduction is explained based on hopping mechanism occuring via polarons.

scholarly journals Dielectric Properties, AC Conductivity, and Electric Modulus Analysis of Bulk Ethylcarbazole-Terphenyl

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Hussam Bouaamlat ◽  
Nasr Hadi ◽  
Najat Belghiti ◽  
Hayat Sadki ◽  
Mohammed Naciri Bennani ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Electric Modulus ◽  
X Ray Diffraction ◽  
X Ray ◽  
Universal Power Law ◽  
Electrical And Dielectric Properties ◽  
Increasing Temperature ◽  
Hopping Model

Electrical and dielectric properties for bulk ethylcarbazole-terphenyl (PEcbz-Ter) have been studied over frequency range 1 kHz–2 MHz and temperature range (R.T –120°C). The copolymer PEcbz-Ter was characterised by using X-ray diffraction. The frequency dependence of the dielectric constant (εr′) and dielectric loss (εr″) has been investigated using the complex permittivity. εr′ of the copolymer decreases with increasing frequency and increases with temperature. AC conductivity (σac) data were analysed by the universal power law. The behaviour of σac increases with increasing temperature and frequency. The change of the frequency exponent (s) with temperature was analysed in terms of different conduction mechanisms, and it was found that the correlated barrier-hopping model is the predominant conduction mechanism. The electric modulus was used to analyze the relaxation phenomenon in the material.

Structural and Magnetic Hysteresis Properties of Co-Zr Substituted Hexagonal Barium Ferrites

2015 ◽  
Vol 7 (1) ◽  
pp. 1346-1351
Author(s):  
Ch.Gopal Reddy ◽  
Ch. Venkateshwarlu ◽  
P. Vijaya Bhasker Reddy
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Magnetic Hysteresis ◽  
Grain Morphology ◽  
Hexagonal Structure ◽  
Ion Composition ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
Barium Ferrites ◽  
Xrd Patterns

Co-Zr substituted M-type hexagonal barium ferrites, with chemical formula BaCoxZrxFe12-2xO19 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), have been synthesized by double sintering ceramic method. The crystallographic properties, grain morphology and magnetic properties of these ferrites have been investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM). The XRD patterns confirm the single phase with hexagonal structure of prepared ferrites. The magnetic properties have been investigated as a function of Co and Zr ion composition at an applied field in the range of 20 KOe. These studies indicate that the saturation magnetization (Ms) in the samples increases initially up to the Co-Zr composition of x=0.6 and decreases thereafter. On the other hand, the coercivity (Hc) and Remanent magnetization (Mr) are found to decrease continuously with increasing Co-Zr content. This property is most useful in permanent magnetic recording. The observed results are explained on the basis of site occupation of Co and Zr ions in the samples.

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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