scholarly journals Electrical transport properties of V2O5-added Ni–Co–Zn ferrites

2021 ◽  
Author(s):  
M. Firoz Uddin ◽  
M. Samir Ullah ◽  
S. Manjura Hoque ◽  
F. A. Khan ◽  
A. A. Momin ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Electrical Transport ◽  
Ac Conductivity ◽  
Complex Impedance ◽  
Frequency Region ◽  
Dielectric Constants ◽  
Bulk Property ◽  
Electrical Transport Properties ◽  
Polarization Model ◽  
Zn Ferrite

Frequency-dependent dielectric constant, dielectric loss, AC conductivity values and complex impedance spectra of V2O5-added Ni–Co–Zn ferrites (Ni[Formula: see text]Co[Formula: see text]Zn[Formula: see text]Fe2O4 + [Formula: see text]V2O5, where [Formula: see text] = 0, 0.5, 1 and 1.5 wt.%) have been investigated at room temperature. The dielectric properties of the samples follow the Maxwell–Wagner polarization model. An inverse relationship was found between dielectric constant and AC electrical resistivity for all the samples. The dielectric constants decreased with the addition of V2O5, while the electrical resistivities of V2O5-added Ni–Co–Zn ferrites are found to be larger than that of pure Ni–Co–Zn ferrite. The AC conductivity was reduced with the addition of V2O5 to Ni–Co–Zn ferrite at lower-frequency region. However, AC conductivity shows a sharp increase at higher-frequency region, which could be attributed to the enhancement of electron hopping between the Fe[Formula: see text] and Fe[Formula: see text] ions in the ferrite matrix due to the activity of the grains. The complex impedance spectroscopy results through Cole–Cole/Nyquist plot have demonstrated a single semicircular arc. It indicates that conduction mechanism takes place predominantly through the grain/bulk property, which could be ascribed to the larger grain size of V2O5-added Ni–Co–Zn ferrites.

Dielectric and ac Conductivity Studies on Nanocrystalline Mn Modified Cobalt Ferrite

2018 ◽  
Vol 24 (8) ◽  
pp. 5629-5632 ◽  
Author(s):  
Sweety Supriya ◽  
Sunil Kumar ◽  
Manoranjan Kar
Keyword(s):  
Dielectric Constant ◽  
Frequency Response ◽  
Electrical Transport ◽  
Ac Conductivity ◽  
Cobalt Ferrite ◽  
Electrical Transport Properties ◽  
Arrhenius Behavior ◽  
Temperature Dependent ◽  
Two Layer Model ◽  
Frequency Temperature

The ac conductivity and dielectric properties on CoFe2−xMnxO4 for x = 0.00, 0.10, 0.15 and 0.20 have been studied in detail. All the samples were prepared in nanocrystalline size. These materials are found to be crystallized to Fd <mml:math display="block"> <mml:semantics> <mml:mover accent="true"> <mml:mi>3</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:semantics> </mml:math> m space group in cubic spinel structure. The dielectric constant and ac conductivity has been discussed as a function of frequency, temperature and composition. The relation between dielectric constant and ac conductivity has been analyzed and the results validate each other. The frequency response of ac conductivity (σac) obeys Johnschers power law and the parameters obtained, explain the sources of ac and dc electrical conductivity in the material. The frequency response of σac follows Maxwell–Wagner two-layer model. The influence of frequency as pumping force on activation energy has been determined. The temperature dependent ac conductivity shows the Arrhenius behavior. The σac observed to be enhanced with increase in frequency as well as temperature. The semiconducting behavior (NTCR) was also evident from temperature dependent electrical transport properties study. The low value of ac conductivity suggests a possible use of this material in dielectric applications.

scholarly journals Magnetic and Electrical Transport Properties of Vanadium Telluride

1980 ◽  
Vol 35 (7) ◽  
pp. 701-703 ◽  
Author(s):  
C. Prasad ◽  
R. A. Singh
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Magnetic Susceptibility ◽  
Electrical Transport ◽  
Powdered Sample ◽  
Neel Temperature ◽  
Electrical Transport Properties ◽  
Néel Temperature ◽  
Paramagnetic Curie Temperature ◽  
Temperature Range

Measurements of the magnetic susceptibility of a powdered sample of VTe in the temperature range 90 - 700 K, and of the a.c. electrical conductivity (σ), thermoelectric power (θ) and dielectric constant (ε′) of pressed pellets of the compound in the temperature range 300 -1100 K are reported. The compound is found to be antiferromagnetic with Neel temperature 420 ± 5 K. The effective paramagnetic moment and paramagnetic Curie temperature are found to be 1.6 μB and - 250 K, respectively. The dependence of σ, θ and ε′ on temperature shows no anomaly at the Neel temperature and is indicative of the metallic nature of the compound.

SYNTHESIS AND CHARACTERIZATION OF COMPLEX FERROELECTRIC OXIDE

2012 ◽  
Vol 02 (04) ◽  
pp. 1250024 ◽  
Author(s):  
PIYUSH R. DAS ◽  
B. N. PARIDA ◽  
R. PADHEE ◽  
R. N. P. CHOUDHARY
Keyword(s):  
Temperature Dependence ◽  
Electrical Transport ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Ferroelectric Properties ◽  
Complex Impedance ◽  
Electrical Transport Properties ◽  
Arrhenius Behavior ◽  
Orthorhombic Crystal ◽  
Grain Distribution

The polycrystalline sample of Li2Pb2Pr2W2Ti4V4O30 was prepared by a solid-state reaction technique. The preparation conditions of the compound have been optimized using thermal analysis (DTA and TGA) technique. Room temperature structural analysis confirms the formation of single phase compound in orthorhombic crystal system. The surface morphology of the sample, recorded by scanning electron microscope, shows uniform grain distribution on the surface of the sample. The observation of hysteresis loop confirmed that the material has ferroelectric properties at room temperature. Electrical properties of the material were studied by complex impedance spectroscopic technique. Temperature dependence of electrical parameters (impedance, modulus, etc.) is strongly correlated to the micro-structural characteristics (bulk, grain boundary, etc.) of the sample. A typical temperature-dependent resistive characteristic of the sample (i.e., negative temperature coefficient of resistance (NTCR)) exhibits its semiconducting properties. The temperature dependence of dc conductivity shows a typical Arrhenius behavior. A signature of ionic conductivity in the system was observed in ac conductivity spectrum. The sample obeys Jonscher's universal power law. The hopping mechanism for electrical transport properties of the system with nonexponential-type conductivity relaxation was suggested from the electrical modulus analysis.

Electrical transport properties and complex impedance investigation of Fe3+ and La3+ co-doping (Pb,Sr)TiO3 thin films

2018 ◽  
Vol 236-237 ◽  
pp. 179-188
Author(s):  
F.M. Pontes ◽  
D.S.L. Pontes ◽  
A.J. Chiquito ◽  
Y.N. Colmenares ◽  
V.R. Mastelaro ◽  
...  
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Electrical Transport ◽  
Complex Impedance ◽  
Electrical Transport Properties ◽  
Co Doping

scholarly journals Electrical transport properties of CoMn0.2−xGaxFe1.8O4 ferrites using complex impedance spectroscopy

AIP Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 055909 ◽  
Author(s):  
Chien-Yie Tsay ◽  
Yi-Hsiang Lin ◽  
Yao-Ming Wang ◽  
Horng-Yi Chang ◽  
Chien-Ming Lei ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Transport Properties ◽  
Electrical Transport ◽  
Complex Impedance ◽  
Complex Impedance Spectroscopy ◽  
Electrical Transport Properties

scholarly journals Structural, Dielectric and Electrical Properties of Sol-Gel Auto-Combustion Technic of CuFeCr0.5Ni0.5O4 Ferrite

2021 ◽  
Author(s):  
Omar Rejeiba ◽  
Fakher Hcini ◽  
Maria Nasri ◽  
Bandar Alzahrani ◽  
Mohamed Lamjed Bouazizi ◽  
...  
Keyword(s):  
Electrical Transport ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Complex Impedance ◽  
Electrical Circuit ◽  
Ac Impedance Spectroscopy ◽  
Electrical Transport Properties ◽  
Wide Range ◽  
Auto Combustion ◽  
Linear Fit

Abstract The CuFeCr0.5Ni0.5O4 (CFO) compound was synthesized using sol-gel reaction combustion technic. The structural analysis showed that the obtained composites have a polycrystalline nature and the cubic spinel structure ( space group). Microstructural analysis revealed the formation of spherical and elongated grains of our sample. The dielectric and electrical transport properties of CuFeCr0.5Ni0.5O4 were investigated in detail by Ac impedance spectroscopy in a wide range of temperature (200 K-400 K) and frequency (100Hz to100KHz). Our results show that the electrical modulus and impedance studies confirm the presence of a relaxation phenomenon with non-Debye type in the prepared sample. The activation energy Edc estimated from the slope of the linear fit plot is equal to 0.158 eV with frequency of 100Hz and 0.126 eV with frequency of 1MHz at temperature range 200K-400K. Close activation energies values were found from analyzes of relaxation time and dc-conductivity indicating that the relaxation and the conduction processes may be attributed to the presence of free carrier charges and impurities at the grain boundaries. The conduction process for samples is described by the NSPT model. The complex impedance analyses and modulus formalism confirm a grain and grain boundary mechanism contributing to the dielectric properties. The real and the imaginary parts of the impedance are well fitted to equivalent electrical circuit (Rg+ Rgb//CPEgb) was used for modeling the Nyquist data.

scholarly journals Synthesis and Study of Structural and Dielectric Properties of Dy-Ho Doped Mn-Zn Ferrite Nanoparticles

2021 ◽  
Author(s):  
Krishtappa Manjunatha ◽  
Veerabhadrappa Jagadeesha Angadi ◽  
Brian Jeevan Fernandes ◽  
Keralapura Parthasarathy Ramesh
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Ferrite Nanoparticles ◽  
The Real ◽  
Low Dielectric ◽  
Zn Ferrite ◽  
Xrd Patterns ◽  
The One

The Dy-Ho doped Mn-Zn Ferrite nanoparticles have been synthesized by solution combustion method using mixture of fuels as glucose and urea. The synthesized samples of structural properties were characterized through XRD (X-ray diffraction) and dielectric properties were studied through impedance analyzer. The XRD patterns of all samples confirms the spinel cubic structure having space group Fd3m. Further all synthesized samples reveal the single-phase formation without any secondary phase. The lattice parameters and hopping lengths were increases with increase of Dy-Ho concentration. SEM micrographs shows the porous nature for all samples. The crystallite size increases with increase of Dy-Ho concentration. The Dielectric properties of all the samples were explained by using Koop’s phenomenological theory. The real part of dielectric constant, imaginary part of dielectric constant and dielectric loss tangent were decreases with increase of frequency. Th AC conductivity increases with increase of frequency. The real part of impedance spectra decreases with increase of frequency for all samples. The Cole-Cole plots shows the one semicircle for all samples. The high ac conductivity and low dielectric loss observed for all samples at high frequency region and this samples are reasonable for power transformer applications at high frequencies.

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