Superparamagnetic contributions, optical band gap tuning and dominant interfacial resistive mechanisms in ferrites nanostructures

Zulqarnain, Muhammad; Ali, Syed Shahbaz; Hira, Uzma; Jing, Feng; Khan, M.I.; Rizwan, Muhammad; Javed, Khalid; Farid, Ghulam; Hasan, M.S.

doi:10.1016/j.jallcom.2021.162431

Cited by 31 publications

(8 citation statements)

References 53 publications

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“…In this range of frequencies, there is a continuous increase in dispersion with the rise of frequency. The observed behaviour suggests the presence of short-range mobility of the charge carrier involved in the conduction process [94,95].…”

Section: Complex Electrical Modulus Analysismentioning

confidence: 87%

“…It implies that charge carriers are mobile over a short distance. The confinement of charge carriers in the potential well might be due to presence of defects or interfacial layers between the grains [94,95]. In summary, the left of the relaxation peak maxima is the area that indicates the conduction process, while the right of the relaxation peak is the relaxation process.…”

Section: Complex Electrical Modulus Analysismentioning

confidence: 96%

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Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Paswan¹,

Pradhan²,

Kumar³

et al. 2022

Phys. Scr.

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In this work, the comparative study on the electrical transport properties of nanocrystalline nickel ferrite (NiFe2O4) and its bulk counterpart has been carried out in detail by using complex impedance spectroscopy in a wide range of frequencies (100 Hz-1MHz) and temperatures (40°C-320°C).The dispersive nature of the dielectric constant and loss factor is explained by the Maxwell-Wagner model and Koop’s phenomenological theory. The value of the dielectric constant for nanocrystalline nickel ferrite is found to be more as compared to its bulk counterpart. The frequency variation dielectric permittivity is well fitted with the modified Debye formula, which suggests the presence of multiple relaxation processes. The temperature dependent ac conductivity follows Jonscher’s universal power law and reveals the presence of multiple transport mechanisms from small polaron hopping (SPH) to correlated barrier hopping (CBH) mechanism near 200°C.The estimated values of Mott parameters are found to be satisfactory. Thermally activated relaxation phenomena have been confirmed by scaling curves of imaginary impedance (Z") and modulus (M"). The comparison between the Z" and M" spectra indicates that both long-range and short-range movement of charge carriers contribute to dielectric relaxation with short-range charge carriers predominating at low temperatures while long-range charge carriers are dominating at high temperatures. Analysis of the semicircular arcs of Nyquist plot indicates the presence of grain boundary contribution to the electrical conduction process for the nanocrystalline sample at high temperatures. The non-Debye type of relaxation has been examined by stretching exponential factor (β) which has been estimated by fitting the modified KWW (Kohlrausch-Williams-Watts) equation to the imaginary electric modulus curve. The value of β is found to be strongly temperature dependent and its value for the nanocrystalline sample is less than that of the bulk system which is explained on the basis of dipole-dipole interaction.

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Section: Complex Electrical Modulus Analysismentioning

confidence: 87%

Section: Complex Electrical Modulus Analysismentioning

confidence: 96%

Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Paswan¹,

Pradhan²,

Kumar³

et al. 2022

Phys. Scr.

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“…The lack of semicircles for all ferrites indicates that the conduction effect of grains is more dominant than the resistive effect of the interfaces. The appearance of such a modulus spectrum indicates that the conduction mechanism exhibits a non-Debye relaxation …”

Section: Resultsmentioning

confidence: 99%

“…59 spectrum indicates that the conduction mechanism exhibits a non-Debye relaxation. 61 ■ CONCLUSIONS…”

mentioning

confidence: 99%

Comprehensive Improvement of Various Features of Cu–Cd Ferrites (Cu_0.5Cd_0.5Fe_2–xCe_xO₄) by Cerium (Ce³⁺) Ion Substitution

Fatima,

Hasan,

Akhtar

et al. 2023

ACS Omega

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Cerium (Ce 3+ ) substitution in Cu−Cd spinel nanoferrites with the compositional formula Cu 0.5 Cd 0.5 Fe 2−x Ce x O 4 (x = 0.0, 0.0125, 0.0250, 0.0375, 0.050) was performed by the hydrothermal route. The structural, morphological, optical, electrical, and dielectric properties of Ce-substituted Cu−Cd ferrites were explored. X-ray diffraction revealed the single-phase cubic structure of all nanoferrites. The average crystallite size (72.42−11.61 nm) and lattice constant (8.419−8.449 Å) were observed for the synthesized ferrites. The surface shapes of particles were determined by scanning electron microscopy. The substitution was also verified by Fourier transform infrared spectroscopy and ultraviolet−visible spectrophotometry. The semiconducting behavior of ferrites was determined from their electrical properties, such as direct current (DC) electrical resistivity. The Curie temperature was observed at 523 K temperature for all nanoferrites. The dielectric constant and dielectric loss significantly indicated the reducing behavior with an increase in the cerium concentration. The sample Cu 0.5 Cd 0.5 Fe 1.975 Ce 0.025 O 4 resulted in the lowest optical bandgap energy, DC resistivity, and dielectric losses. The nature of the electrical resistivity and dielectric constants indicate that the designed materials are highly appropriate for the design of microwave gadgets.

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“…This overlap depends on the position of the oxygen anions, represented as the oxygen parameter (u), which is 0.250 for the non-distorted and ideal octahedral site. [12,23] Higher values of u represent the increasing volume of the tetrahedral site that accompanies decreasing the volume of the octahedral site. [24] The value of u shifts to fit the cations at interstitial sites according to their ionic radii.…”

Section: Introductionmentioning

confidence: 99%

Electrical Effects of Ionic Deficient Cubic Ferrite Spinels: A Case Study on MgFe₂O₄

Farshidfar,

Oreskovic,

Ryan

et al. 2023

Advanced Physics Research

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Electron transport via indirect exchange interactions between octahedral sites in spinels is affected by cationic or anionic vacancies. Thus, the deviation of the electron hopping mechanism is investigated, from a constant energy barrier toward a variable range energy barrier in iron‐deficient and oxygen‐deficient cubic magnesium ferrite spinels. Variable range electron hopping activation energy at high temperatures is consistent with the modified cation–anion interactions in the distorted structure of an ionic deficient cubic magnesium ferrite spinel. For these observations, an instrumental method is developed to evaluate the electron exchange interactions and general redox kinetics on surfaces, managed by exposure to the flow of a wide variety of desired gases. The applications of this instrument are far beyond the example studies reported here.

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Superparamagnetic contributions, optical band gap tuning and dominant interfacial resistive mechanisms in ferrites nanostructures

Cited by 31 publications

References 53 publications

Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Comprehensive Improvement of Various Features of Cu–Cd Ferrites (Cu_0.5Cd_0.5Fe_2–xCe_xO₄) by Cerium (Ce³⁺) Ion Substitution

Electrical Effects of Ionic Deficient Cubic Ferrite Spinels: A Case Study on MgFe₂O₄

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Superparamagnetic contributions, optical band gap tuning and dominant interfacial resistive mechanisms in ferrites nanostructures

Cited by 31 publications

References 53 publications

Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Electrical transport properties of nanocrystalline and bulk nickel ferrite using complex impedance spectroscopy: a comparative study

Comprehensive Improvement of Various Features of Cu–Cd Ferrites (Cu0.5Cd0.5Fe2–xCexO4) by Cerium (Ce3+) Ion Substitution

Electrical Effects of Ionic Deficient Cubic Ferrite Spinels: A Case Study on MgFe2O4

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Product

Resources

About

Comprehensive Improvement of Various Features of Cu–Cd Ferrites (Cu_0.5Cd_0.5Fe_2–xCe_xO₄) by Cerium (Ce³⁺) Ion Substitution

Electrical Effects of Ionic Deficient Cubic Ferrite Spinels: A Case Study on MgFe₂O₄