Infrared and structural studies of Mg1–xZnxFe2O4 ferrites

Mohammed, K.A.; Al-Rawas, A. D.; Gismelseed, A. M.; Sellai, A.; Widatallah, H. M.; Yousif, A. A.; Elzain, M. E.; Shongwe, Musa S.

doi:10.1016/j.physb.2011.12.097

Cited by 211 publications

(79 citation statements)

References 38 publications

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“…Usually the electrical conductivity in ferrites may explain on the basis of Verwey conduction mechanism, where the electron exchange takes place between the adjacent Fe 2+ and Fe 3+ ions which occupied the octahedral sites [38]. From Figure 4, it was found that the AC conductivity increased linearly with frequency of applied field, this shows the general behaviour of ferrite structures.…”

Section: Ac Conductivitymentioning

confidence: 82%

Dielectric Response of Nix Zn1-x Al Fe O4 Nanoferrites

Donta¹,

Katrapally²,

Pendyala³

2016

NanoWorld J

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Ni-Zn-Al nanoferrites of general formula Ni x Zn 1-x Al Fe O 4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by sol-gel auto combustion technique. The X-ray diffraction and FTIR studies confirmed the formation of single cubic spinel structure. Dielectric performance and AC conductivity of prepared mixed nanoferrites were carried out using LCR impedance meter. It was observed that both dielectric constant and dielectric loss were decreased by increasing the frequency whereas AC conductivity increases with applied frequency but decreases with increasing the Ni 2+ ion substitution for a fixed Al 3+ ion concentration. DC resistivity, activation energy and Curie temperature were calculated by using the two probe experimental method. It was observed that DC resistivity decreased whereas the charge mobility increased with increasing the temperature. DC resistivity and activation energy of the nanoferrite samples were increased with Ni 2+ ion substitution for a fixed Al 3+ ion concentration.

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Section: Ac Conductivitymentioning

confidence: 82%

Dielectric Response of Nix Zn1-x Al Fe O4 Nanoferrites

Donta¹,

Katrapally²,

Pendyala³

2016

NanoWorld J

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“…The cation distribution for the basic sample is shown below. In the available literature [9,11], it was reported that magnesium has a strong preference for octahedral sites, thus, in case of magnesium substituted samples strong octahedral preference of magnesium is taken into account. Intensity ratios were calculated for all magnesium substituted compositions by varying the concentration of magnesium over tetrahedral and octahedral sites, i.e.…”

Section: Cation Distributionmentioning

confidence: 99%

Structural and dielectric studies of Mg2+ substituted Ni–Zn ferrite

Prasad

Babu²,

Prasad

2015

Materials Science-Poland

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Polycrystalline ferrites having the chemical formula Ni 0.65−x Zn 0.35 Mg x Fe 2 O 4 (0 x 0.2) were prepared by solid state reaction route in steps of x = 0.04. The effect of incorporation of diamagnetic divalent magnesium at expense of nickel on the structural properties of these ferrites has been studied. The proposed cation distribution was derived from theoretical X-ray diffraction intensity calculations. These intensity calculations were done by varying the concentration of magnesium ions over two sites in the lattice. For a certain amount of magnesium concentration, the calculated and observed X-ray diffraction intensities were found to be in good agreement. Site occupancy of divalent diamagnetic magnesium was established from this cation distribution. The octahedral environment facilitates magnesium to enter the B-site at about 95 % and the remaining 5 % occupy tetrahedral sites (A-sites). The movements of cations between tetrahedral and octahedral sites as a result of magnesium substitution were discussed in the view of structural parameters, such as tetrahedral and octahedral bond lengths, cation-cation and cation-anion distances, bond angles and hopping lengths, which were calculated using experimental lattice constants and oxygen parameters. All structural parameters showed slight deviations from ideal values. Among all magnesium substituted samples, the ones with x = 0.12 exhibited insignificant variation in view of structural properties. Dielectric measurements were conducted at a standard frequency of 1 kHz. Large values of the recorded dielectric constants displayed typical characteristics of bulk ferrites. Both dielectric constant and loss values showed mixed variations, attributed to the loss of zinc ions during the sintering process.

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“…( ionic radius of 0.66 Å) with the larger radius Fe 3+ ions at the octahedral sites [10]. For a high concentration of zinc (e.g., x = 1) a decrease in the lattice parameter is observed, which may be attributed to the shifting of some of the Fe 3+ ions from site A to site B [5].…”

Section: Structural Propertiesmentioning

confidence: 99%