Electrical and dielectric properties of the Ca2MnO4−δ system

Chihaoui, Nejla; Dhahri, R.; Bejar, M.; Dharhi, E.; Costa, L.C.; Graça, M.P.F.

doi:10.1016/j.ssc.2011.06.023

Cited by 32 publications

(9 citation statements)

References 21 publications

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“…As seen these two values are very close, which implies that the relaxation process may be attributed to the same type of charge carriers. It is worth noticing that the results of activation energies are in the same order of magnitude with other materials based on manganese and it is in a accordance with literature [23,28].…”

Section: Conductivitysupporting

confidence: 90%

See 1 more Smart Citation

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Omri

Bejar

Dhahri

et al. 2012

Journal of Alloys and Compounds

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Section: Conductivitysupporting

confidence: 90%

“…This is very much consistent with the impedance data. The electric modulus M ⁄ represents the real dielectric relaxation process and should be replaced by a frequency-dependent electric modulus which can be expressed by the following equation [23][24][25]:…”

Section: Electrical Modulus Analysismentioning

confidence: 99%

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Omri

Bejar

Dhahri

et al. 2012

Journal of Alloys and Compounds

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“…1. It can be seen that all samples present a single phase and it was verified that the sample with δ=0.0 crystalizes in the tetragonal structure becoming orthorhombic for δ>0.0 samples [6,7]. The morphological analysis, made by SEM microscopy, shows a decrease in the size of the grains with the increase of δ value.…”

Section: Resultsmentioning

confidence: 74%

“…Nowadays research about layered perovskites has been motivated by their wide variety of physical properties such as colossal magnetoresistance [1,2], superconductivity [3], ferroelectricity [4], and for their possible use in spintronic devices [5]. Currently, magnetocaloric effect (MCE) offers an intelligent alternative technology for refrigeration, with enhanced efficiency without environmental hazards [6].…”

Section: Introductionmentioning

confidence: 99%

Dielectric spectroscopy of Ca₂MnO_4‐δ ceramics using equivalent circuit analysis

Chihaoui

Bejar

Dhahri

et al. 2013

Phys. Status Solidi C

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In the last years a growing interest in the study of layered perovskites which acquire a wide variety of interesting and useful physical properties such as colossal magnetoresistance, superconductivity, ferroelectricity is quite visible. From those properties, the magnetocaloric effect (MCE) offers an interesting alternative technology for refrigeration. On other hand, their possible use in spintronic devices has also attracted much attention.In this work, the effect of the creation of vacancies in oxygen sites on the structure of Ca2MnO4‐δ Ruddlesden‐Popper (RP) compounds, prepared by sol‐gel method, was studied mainly through their structural, morphologic and dielectric properties. The cationic stoichiometry of the samples was studied using energy dispersive X‐ray analysis (EDAX). EDAX spectra showed a nominal composition close to the desired one. The structural study, by X‐ray diffraction analysis, confirmed the single‐phase composition of all the samples. The dielectric studies, the temperature range between 80 K and 360 K, showed dielectric relaxation phenomena, which were related to the Mn4+/Mn3+ ratio. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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“…This confirms the above reported impedance results. The electric modulus M ∗ signifies the real dielectric relaxation phenomenon and can be expressed as:

M^{*} = M_{\infty} true[1 - {true \int}_{\infty}^{0} true(- \frac{d ϕ true(t true)}{d t} true) \exp true(- j ω t true) d t true]

where

M_{\infty} = 1 / {normalϵ}_{\infty}

is reciprocal of high frequency dielectric constant

ϕ true(t true) = \exp true[- true(t / τ_{M} true) true]

ϕ true(t true)

is the time evolution of the electric field and

τ_{M}

is the conductivity relaxation time.…”

Section: Resultsmentioning

confidence: 99%

DC Electrical Resistivity, Dielectric, and Magnetic Studies of Rare‐Earth (Ho³⁺) Substituted Nano‐Sized CoFe₂O₄

Routray

Saha

Behera

2019

Physica Status Solidi (b)

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The effect of Fe substitution by rare‐earth (Holmium; Ho3+) ions in CoFe2O4 (CFO) prepared by glycine nitrate process is investigated from electrical, dielectric, magnetic, and Mössbauer perspectives. The anticipated spinel cubic phase structure is confirmed by X‐ray diffractometry and Fourier transform infrared (FTIR) analysis which support the presence of a secondary phase of HoFe2O3 at higher Ho content. Field emission scanning electron microscope (FESEM) and transmission electron microscopic (TEM) micrographs confirmed that the incorporation of Ho3+ significantly reduced the grain size of the samples from 50 nm to 20 nm. The complex impedance and modulus spectroscopy are investigated as a function of frequency in the regime of 102–106Hz in the temperature range of 30–300 °C. The conduction mechanism is attributed to the hopping of both electrons and holes. Activation energies (Ea) obtained from the Arrhenius plots of the grain and the grain boundary conductions are ascribed to the hopping of charge carriers. Electrical modulus results specify the existence of the non‐Debye type of dielectric relaxation. A massive reduction in loss factor is successfully achieved. Room temperature magnetization measurements indicate a reduction in saturation magnetization and coercivity (hysteresis losses) with increasing Ho3+ content, which entails these materials to be used for magnetic data storage and magneto recording devices.

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Electrical and dielectric properties of the Ca2MnO4−δ system

Cited by 32 publications

References 21 publications

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Dielectric spectroscopy of Ca₂MnO_4‐δ ceramics using equivalent circuit analysis

DC Electrical Resistivity, Dielectric, and Magnetic Studies of Rare‐Earth (Ho³⁺) Substituted Nano‐Sized CoFe₂O₄

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Electrical and dielectric properties of the Ca2MnO4−δ system

Cited by 32 publications

References 21 publications

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Electrical conductivity and dielectric analysis of La0.75(Ca,Sr)0.25Mn0.85Ga0.15O3 perovskite compound

Dielectric spectroscopy of Ca2MnO4‐δ ceramics using equivalent circuit analysis

DC Electrical Resistivity, Dielectric, and Magnetic Studies of Rare‐Earth (Ho3+) Substituted Nano‐Sized CoFe2O4

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Product

Resources

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Dielectric spectroscopy of Ca₂MnO_4‐δ ceramics using equivalent circuit analysis

DC Electrical Resistivity, Dielectric, and Magnetic Studies of Rare‐Earth (Ho³⁺) Substituted Nano‐Sized CoFe₂O₄