Conduction mechanism and dielectric properties of ZnO/MgO solid composites

Hafef, Olfa; Othman, Zayani Jaafar; Megdich, Makram; Matoussi, Adel

doi:10.1007/s00339-016-0721-4

Cited by 11 publications

(4 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We located a considerable reduction of the imaginary part ε ″ with the rate of the Mg doping which confirms the rule of the space charge [ 61 ] (see Figure 10 a). The same performance was also monitored by Hafef et al [ 24 ] with high MgO-doping rates (10% and 20% of MgO). This also was explained by the separation of the MgO phase in the ZnO host matrix.…”

Section: Resultssupporting

confidence: 66%

“…Earlier studies confirm the encouraging performances of the electrical and dielectric properties of ZnO:Mg in numerous applications. O. Hafef et al [ 24 ] demonstrated the decrease in AC conductivity with increasing MgO concentration in ZnO/MgO composites. This has been assigned to the sintering technique where ions scattering form deep donor levels in the band gap.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

et al. 2022

View full text Add to dashboard Cite

Magnesium-doped zinc oxide “ZnO:Mg” nanocrystals (NCs) were fabricated using a sol gel method. The Mg concentration impact on the structural, morphological, electrical, and dielectric characteristics of ZnO:Mg NCs were inspected. X-ray diffraction (XRD) patterns display the hexagonal wurtzite structure without any additional phase. TEM images revealed the nanometric size of the particles with a spherical-like shape. The electrical conductivity of the ZnO NCs, thermally activated, was found to be dependent on the Mg content. The impedance spectra were represented via a corresponding circuit formed by a resistor and constant phase element (CPE). A non-Debye type relaxation was located through the analyses of the complex impedance. The conductivity diminished with the incorporation of the Mg element. The AC conductivity is reduced by raising the temperature. Its plot obeys the Arrhenius law demonstrating a single activation energy during the conduction process. The complex impedance highlighted the existence of a Debye-type dielectric dispersion. The various ZnO:Mg samples demonstrate high values of dielectric constant with small dielectric losses for both medium and high-frequency regions. Interestingly, the Mg doping with 3% content exhibits colossal dielectric constant (more than 2 × 104) over wide temperature and frequency ranges, with Debye-like relaxation. The study of the electrical modulus versus the frequency and at different temperatures confirms the non-Debye relaxation. The obtained results reveal the importance of the ZnO:Mg NCs for device applications. This encourages their application in energy storage.

show abstract

Section: Resultssupporting

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

et al. 2022

View full text Add to dashboard Cite

show abstract

“…One outcome is a relatively open mullite network (1/2 O 2is no longer compensated by additional Mg 2+ ), which might explain the increased hydrophilicity of the MgMul-1450 sample. Additionally, interstitial and/or segregation of Mgrelated phases at grain boundaries are two further options to be considered according to several studies from the literature [42][43][44]. Regarding the surface characteristics of the MgMul-1450 membrane, the vapor adsorption clearly demonstrated an increment in hydrophilic behavior (Ratio Water/n-Heptane = 14) owing to MgO incorporation, as aforementioned.…”

Section: Discussionmentioning

confidence: 98%

Effect of MgO on the microstructure and properties of mullite membranes made by phase-inversion tape casting

Nishihora

Rudolph

Quadri

et al. 2021

Journal of Asian Ceramic Societies

View full text Add to dashboard Cite

Flat microfiltration mullite (3Al 2 O 3 2SiO 2 ) membranes were prepared via phase-inversion tape casting method. The sintering temperature has been reduced from 1700°C to 1450°C by adding 3 wt.% of magnesium oxide (MgO) as a sintering aid. The effect of this compound on the membrane properties was systematically investigated. The presence of MgO promoted at the same time a change in membrane morphology resulting in a symmetric structure, which is opposite to the asymmetrical structure obtained for mullite membranes prepared without this sintering aid. Porosity of 38.9% and average pore size of 2.33 μm was achieved. Water and n-heptane vapor adsorption analysis showed an increment in hydrophilic behavior due to MgO. The reduction of sintering temperature from 1700°C (MgO free) to 1450°C (MgO added) produced mechanical stable samples with flexural strength about 15.3 MPa. The membrane was resistant enough to withstand the water flux permeation test up to 3 bar. Compared to the pure mullite membranes, the MgO containing sample displayed higher water permeation fluxes, which might be related to both the larger superficial pore size and its hydrophilicity.

show abstract

“…These are: (i) Non-overlapping Small Polaron Tunneling (NSPT) part where n increases with increase in temperature and (ii) the correlated barrier hopping model (CBH) where 'n' decreases with increasing temperature. The temperature below the 150 °C NSPT model is applicable for increasing n with rising in temperature [59]. The affected atom is believed to be screened by an electron charge cloud which generates the interaction between the electron and phonon cloud and the polaron (quasi-particle) tunneling occur to contribute to the conduction process.…”

Section: Ac Conductivitymentioning

confidence: 99%

Structural, dielectric and electrical characteristics of manganese modified (Bi_0.5Ba_0.25Sr_0.25) (Ti_0.5Fe_0.5)O₃ relaxor

Auromun¹,

Choudhary²

2021

Phys. Scr.

View full text Add to dashboard Cite

In this communication, detailed studies of the structural, microstructural, dielectric, and electrical properties of polycrystalline materials, (Bi0.5Ba0.25Sr0.25) (Ti0.5Fe0.5)O3 and (Bi0.5Ba0.25Sr0.25) (Ti0.25Mn0.25Fe0.5)O3, synthesized by using a high–temperature solid-state-reaction method, have been reported. X-ray structural and scanning electron micrograph studies exhibit phase pure tetragonal system and surface morphology (size and distribution of grains and grain boundaries) of the samples respectively. Analysis of the temperature and frequency dependence of dielectric and electrical (impedance, modulus, and conductivity) data reveals the ferroelectric relaxor behavior, relaxation mechanism, and semiconductor (negative temperature coefficient of resistance) properties of the bulk BFBST and Mn modified BFBST electro-ceramics. The relaxation time and activation energy (Ea) were calculated from the above data. The characteristics of Mn modified BFBST have been compared to that of it’s parent (BFBST) compound. The different inherent conduction mechanisms, such as Ohmic, hopping, space charge limited (SCLC) have been analyzed. The bulk- and interface-limited conduction processes were evidently found in the materials by the Poole–Frenkel (PF) and Schottky (SEmen modified BFBST have been compared to that of its parent (BFBST) compound) emission fitting of the J ∼ E characteristic data. The leakage data of BFBST-Mn (Mn modified Mn) quantified the average energy gap (Eg) in the range of 0.83–0. 87 eV for different applied voltages and in a wide range of temperature (25 °C–300 °C). With the increase in voltage, Eg decreases. This work suggests that Mn-substitution (Mn4+) at B (Ti4+) site keeping the stoichiometry undisturbed enhances structural, dielectric response (higher dielectric constant) and reduce the leakage behavior especially at low temperature and high-frequency range.

show abstract

Conduction mechanism and dielectric properties of ZnO/MgO solid composites

Cited by 11 publications

References 54 publications

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

Effect of MgO on the microstructure and properties of mullite membranes made by phase-inversion tape casting

Structural, dielectric and electrical characteristics of manganese modified (Bi_0.5Ba_0.25Sr_0.25) (Ti_0.5Fe_0.5)O₃ relaxor

Contact Info

Product

Resources

About

Conduction mechanism and dielectric properties of ZnO/MgO solid composites

Cited by 11 publications

References 54 publications

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications

Effect of MgO on the microstructure and properties of mullite membranes made by phase-inversion tape casting

Structural, dielectric and electrical characteristics of manganese modified (Bi0.5Ba0.25Sr0.25) (Ti0.5Fe0.5)O3 relaxor

Contact Info

Product

Resources

About

Structural, dielectric and electrical characteristics of manganese modified (Bi_0.5Ba_0.25Sr_0.25) (Ti_0.5Fe_0.5)O₃ relaxor