Structural and dielectric properties of copper-based spinel ferrites

Farid, Hafiz Muhammad Tahir; Ahmad, Ishtiaq; Ali, Irshad; Mahmood, Asif; Ramay, Shahid M.

doi:10.1140/epjp/i2018-11832-4

Cited by 30 publications

(10 citation statements)

References 33 publications

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“…The presence of two regions separated by a kink, at a Curie temperature of 327 K, suggests the presence of a transition in the system from ferrimagnetic (low temperature region) to paramagnetic (high temperature region) at each frequency. Similar behaviour has been reported in ferrites by other researchers also [33][34][35]. The activation energy E dc has been calculated from the slope of each region by the relation σ dc = σ o exp( E dc /k B T ) and is presented in table 2.…”

Section: Imaginary Impedance (Z')supporting

confidence: 72%

“…The temperature dependent exponent 'n' has a value lying between 0.679 and 0.735 as shown in table 3 and is numerically best fitted into a polynomial of degree six. It is observed to decrease and increase alternately with temperature, indicating that the ac conductivity mechanism in our sample can be represented by the overlapping large polaron tunnelling (OLPT) model [33]. Parameter A which represents the intensity of polarizability is found to lie in the range 4 × 10 −9 -6 × 10 −9 .…”

Section: Ac Conductivity (σ Ac )mentioning

confidence: 66%

“…The Jonscher's power law σ ac = Aω n is used to determine n from the plot of σ ac versus f graph on log-log scale [27,40,41]. The value of n determines the nature of the conduction mechanism and has been plotted in figure 8 [33]. The temperature dependent exponent 'n' has a value lying between 0.679 and 0.735 as shown in table 3 and is numerically best fitted into a polynomial of degree six.…”

Section: Ac Conductivity (σ Ac )mentioning

confidence: 99%

See 2 more Smart Citations

Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures

Rani,

Kaushik,

Saya

et al. 2023

Mater. Res. Express

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This work reports the fabrication of novel zinc ferrite-copper sulphide (ZnFe2O4/Cu2S) 3D heterostructures and subsequent investigation of the spectroscopic behaviour of various electrical parameters like conductivity, impedance and dielectric loss. The study reveals a non-monotonic behaviour of the real component of impedance (Z'), while the imaginary component of impedance (Z") exhibits a temperature-dependent relaxation frequency, with an estimated activation energy (Ea) of 220.13 meV. The dc conductivity (σdc) measurements reveal the semiconducting nature of the sample and a transition from a ferrimagnetic to a paramagnetic behaviour is reported at the Curie temperature of 327K. In case of ac conductivity (σac), Jonscher's power law σac = Aωn is followed and the exponent n is found to lie in the range 0.679 - 0.735 at different temperatures, which is best fitted into a polynomial of degree six. The temperature variation of n is suggestive of the overlapping large polaron tunnelling (OLPT) model. Further, ac activation energy (Eac) is also calculated, which is found to be smaller than the dc activation energy (Edc), indicating electron hopping between Fe3+ and Fe2+ ions. The numerically computed staying time (τ) of electrons in Fe3+/Fe2+ ionic sites varies with frequency as well as with temperature, ranging from 10-6s to 10-19s. A significant decrease in dielectric loss (tanδ) to the tune of 99% (from 75 at ~100Hz to 0.89 at ~1MHz) is reported at room temperature. In the present scenario, when smart materials like spinel ferrites have garnered significant attention for their promising magnetic and electric properties, our studies of the novel ZnFe2O4/Cu2S 3D heterostructures may provide immense possibilities for tailored applications in various electromagnetic applications.

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Section: Imaginary Impedance (Z')supporting

confidence: 72%

Section: Ac Conductivity (σ Ac )mentioning

confidence: 66%

Section: Ac Conductivity (σ Ac )mentioning

confidence: 99%

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Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures

Rani,

Kaushik,

Saya

et al. 2023

Mater. Res. Express

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“…Various methods such as ball milling method, citrate precursor method, co-precipitation method [11,30], hydrothermal method [31], Pechini method [32], micro emulsion method [33], solid-state method [34,35], solution-combustion method [11], and sol gel auto combustion method [32,[36][37][38] have already been put to use for SrM synthesis (in pure and doped form). Literature survey shows that sol gel auto combustion has several benefits over other techniques [11,[39][40][41][42]. These benefits include low cost, simplicity, lower phase formation temperature and better control over grain size.…”

Section: Introductionmentioning

confidence: 99%

Tailoring the magnetic properties of M-type strontium ferrite with synergistic effect of co-substitution and calcinations temperature

Godara

Kaur

Narang

et al. 2021

Journal of Asian Ceramic Societies

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SrFe 12 O 19 samples were initially prepared using sol-gel auto-combustion method and calcined from 500 to 1100°C (for 6 h). XRD data established the phase formation temperature of SrM phase to be ≈1000°C. Thereafter, the effect of Zn 2+ -Zr 4+ co-dopant on magnetic and structural properties of SrZn x Zr x Fe 12-2x O 19 (x = 0.00-1.00) samples calcined between 900-1100°C was investigated. XRD data shows that the cell volume increases (from 690.45Å 3 (x = 0.00) to 705.72Å 3 (x = 1.00)) while crystallite size decreases (from 123.9 nm (x = 0.00) to 62.3nm (x = 1.00)) calcined at 1000°C. The Rietveld refinement of XRD data confirms a) x = 0.00 sample to be phase pure and b) the presence of ZnFe 2 O 4 (≈2.25) & SrZrO 3 (≈2.93%) impurity phases in x = 1.00 sample, calcined at 1000°C. FESEM micrographs revealed that a) grain size decreases for x > 0.20 with `x' at 900°C and b) increases from 122 nm at 900°C to 443 nm at 1100°C, for x = 0.00. Broadening of Raman bands reveals generation of strain in the lattice with enhancement of Zn 2+ -Zr 4+ concentration. The magnetic studies reveal that the coercivity monotonically decreases (from 5358(x = 0.00) Oe to 690(x = 1.00) Oe at 1000°C) with enhancement of Zn 2+ -Zr 4+ concentration. A maximum M s value ≈ 70.89 emu/g was observed in x = 0.20 sample at 1100°C. M s value also decreases for x > 0.20 at each calcination temperature.

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“…The cation distribution on A and B sites, in general is represented by: [M 2+ δ Fe 3+ 1-δ ] A [M 2+ 1-δ Fe 3+ 1+δ ] B O 2- 4 , where δ = 1 for normal spinel structure and δ = 0 for inverse spinel structure. The distribution of cations among the tetrahedral and octahedral site play an important role in deciding the electric, dielectric, magnetic and structural properties of spinel ferrites [9, 10].…”

Section: Introductionmentioning

confidence: 99%

Ferrites: magnetic materials as an alternate source of green electrical energy

Kharbanda

Madaan

Sharma

et al. 2019

Heliyon

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Ferrites samples Mg1-xLixFe2O4 for x = 0.0, 0.1, 0.2, 0.3, were synthesized by solid-state sintering method. Detailed investigations were made on the structural, morphological, magnetic and electrical proprieties of these samples. A detailed investigation was performed on power generation of these samples and role of Li-doping has been discussed. The X-ray Diffraction (XRD) pattern confirms the spinel phase formation in samples without any impurity. It is observed from Scanning Electron Microscopy that average grain size of samples decreases with lithium doping in MgFe2O4. The saturation magnetization of MgFe2O4 (15.4 emu/g) is found to increase with Lithium percentage and maximum 39.3 emu/g for Mg0.7Li0.3Fe2O4 sample. Ferrites play a crucial role in magnetic recording, microwave magnetic devices and many applications in medical sciences. Recently, it was observed that ferrites can be an alternate source of green energy by inventing hydroelectric cell (HEC). The processes of water adsorption and dissociation on the metal-oxide surface, plays an important role in production of electricity in ferrites. When, water is sprayed on hydroelectric cell the thermodynamic driving force is responsible for the formation of stable metal-oxygen or metal-hydroxyl bonds. The reactivity of ferrite surface towards water is based on the interaction of these ions and the d orbital of the Fe atom. Due to this interaction, water dissociated in H3O+ and OH− ions and migrates toward silver and zinc electrodes respectively. A typical hydroelectric cell of 2 inch diameter produces 17.1 mA of peak current and 949 mV voltage with a maximum output power of 15.85 mW for Li = 0.2 doped MgFe2O4 sample.

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Structural and dielectric properties of copper-based spinel ferrites

Cited by 30 publications

References 33 publications

Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures

Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures

Tailoring the magnetic properties of M-type strontium ferrite with synergistic effect of co-substitution and calcinations temperature

Ferrites: magnetic materials as an alternate source of green electrical energy

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Structural and dielectric properties of copper-based spinel ferrites

Cited by 30 publications

References 33 publications

Structural, electrical and dielectric properties of ZnFe2O4/Cu2S 3D heterostructures

Structural, electrical and dielectric properties of ZnFe2O4/Cu2S 3D heterostructures

Tailoring the magnetic properties of M-type strontium ferrite with synergistic effect of co-substitution and calcinations temperature

Ferrites: magnetic materials as an alternate source of green electrical energy

Contact Info

Product

Resources

About

Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures

Structural, electrical and dielectric properties of ZnFe₂O₄/Cu₂S 3D heterostructures