Effect of cation concentration on the relaxation phenomena of Co-Zn ferrite

Ahmed, Mohamed; Darwish, K. A.; Mikhail, H.; Mounir, Mohamed; El-Khawas, E. H.

doi:10.1088/0031-8949/55/6/018

Cited by 9 publications

(3 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The variation in dielectric constant (ε I ) with frequency at room temperature for the samples Co (0.5-x) Ni x Zn 0.5 Fe 2 O 4 with x = 0.0, 0.1, 0.2 and 0.3 is shown in Figure 3 The dielectric constant is found to be less than bulk sample for a frequency of 100 KHz at room temperature. The dielectric constant for bulk Co 0.5 Zn 0.5 Fe 2 O 4 as reported by M. A. Ahmed [15] is 105, whereas in the present investigation the dielectric constant for Co 0.5 Zn 0.5 Fe 2 O 4 with particle size 10 nm is calculated as 28. This low dielectric loss is attributed to homogeneity, better symmetry and small grain size when compared with bulk sample [16].…”

Section: Dielectric Constantcontrasting

confidence: 42%

Synthesis, Structural and Dielectric Studies of Nickel Substituted Cobalt-Zinc Ferrite

Sathishkumar¹,

Venkataraju²,

Sivakumar³

2010

MSA

View full text Add to dashboard Cite

Nano particles of Co(0.5-x)NixZn0.5Fe2O4 (x = 0 to 0.3) is prepared by co-precipitation method. The X-ray diffraction analysis indicates the formation of single phase ferrite particle in nano size. The lattice constant for Co0.5Zn0.5Fe2O4 is found to be 8.38 Å, but the lattice constant decreases when cobalt is replaced by nickel up to x = 0.2 content. The formation of Fe2+ in octahedral site increases the lattice constant for the concentration x = 0.3. The dielectric constant of Co0.5Zn0.5Fe2O4 is found to be less than the bulk sample. The migration of Fe3+ ion from octahedral site to tetrahedral site decreases the dielectric constant with increase in nickel concentration. The charge libration and electron hoping together form the basis for the conduction mechanism in this present compound

show abstract

Section: Dielectric Constantcontrasting

confidence: 42%

Synthesis, Structural and Dielectric Studies of Nickel Substituted Cobalt-Zinc Ferrite

Sathishkumar¹,

Venkataraju²,

Sivakumar³

2010

MSA

View full text Add to dashboard Cite

show abstract

“…They reported that the samples with smaller grain size show only one semicircle corresponding to grain boundary conduction, while samples of larger size show two semicircles corresponding to both grain and grain boundary conduction mechanisms. Ahmed et al [13] studied the effect of cation concentration on the relaxation phenomena of Co-Zn ferrites. Although the magnetic properties of Mn-Ni-Zn ferrites have been studied [14,15], complex impedance spectroscopy studies of the Mn-Ni-Zn ferrites have not been found extensively in the literature.…”

Section: Introductionmentioning

confidence: 99%

Electrical transport properties of Mn–Ni–Zn ferrite using complex impedance spectroscopy

Rahman

Hossain

2014

Phys. Scr.

View full text Add to dashboard Cite

Polycrystalline Mn 0.45 Ni 0.05 Zn 0.50 Fe 2 O 4 was prepared by a standard solid state reaction technique. We report the electrical properties of this ferrite using ac impedance spectroscopy as a function of frequency (20 Hz-10 MHz) at different temperatures (50-350 • C). X-ray diffraction patterns reveal the formation of cubic spinel structure. Complex impedance analysis has been used to separate the grain and grain boundary resistance of this ferrite. The variation of grain and grain boundary conductivities with temperature confirms semiconducting behavior. The dielectric permittivity shows dielectric dispersion at lower frequency and reveals that it has almost the same value on the high-frequency side. The non-coincidence of peaks corresponding to modulus and impedance indicates deviation from Debye-type relaxation. A similar value of activation energy is obtained from impedance and modulus spectra, indicating that charge carriers overcome the same energy barrier during relaxation. Electron hopping is responsible for ac conduction in this ferrite. The electron hopping shifts toward higher frequency with increasing temperature, below which the conductivity is frequency independent. The frequency-independent ac conductivity has been observed at and above 300 • C in the frequency range 20 Hz-1 MHz. This frequency-independent ac conductivity is due to the long-range movement of the mobile charge carriers.

show abstract

“…They reported that the samples with smaller grain size show only one semi-circle corresponding to grain boundary conduction, while samples of larger size show two semi-circles corresponding to both grain and grain boundary conduction mechanism. Ahmed et al [15] studied the effect of cation concentration on the relaxation phenomena of Co-Zn ferrites. They reported that the maximum of the relaxation time (), calculated from the Cole-Cole plots corresponds to the critical concentration, x = 0.6.…”

Section: Introductionmentioning

confidence: 99%