AC conductivity and dielectric properties of SiO2–Na2O–B2O3–Gd2O3 glasses

Mahani, Ragab; Marzouk, Samir Y.

doi:10.1016/j.jallcom.2013.05.173

Cited by 66 publications

(9 citation statements)

References 38 publications

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“…At low frequencies, M 0 exhibited very small values and tended to zero and, thus, suggesting the suppression of the electrode polarization effect. 41 As the frequency increased, M 0 climbed to a maximum asymptotic value dened as M 00 N due to the distribution of relaxation processes over a range of frequencies. Both samples produced a two-step decrease in M 0 in the measured temperature range, while the NCS-CP peaks shied to one step above 533 K. Correspondingly, M 00 showed two peaks in the same temperature range.…”

Section: Frequency and Temperature Dependence Of The Electric Modulus Formalismsmentioning

confidence: 96%

The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework

et al. 2020

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Section: Frequency and Temperature Dependence Of The Electric Modulus Formalismsmentioning

confidence: 96%

The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework

et al. 2020

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“…The frequency dependence of R ω at a selected temperature ( T = 383 K) (inset of Figure 6B) demonstrates an opposites trend to temperature, where it decreases rapidly with increasing frequency. The minimum in the S – T curve (Figure 6A) can be described by the following relation 75

S_{\min} = 1 - \frac{5}{2 {((), \frac{2 α r_{p} W_{H_{0}}}{k_{B} T})}^{\frac{1}{2}}}

The change of conduction mechanism from OLPT to SPT with increasing temperature was reported for ceramics, 77–79 glasses, 80 organic–inorganic hybrids, 81,82 and polymers 83,84 …”

Section: Resultsmentioning

confidence: 87%

“…The change of conduction mechanism from OLPT to SPT with increasing temperature was reported for ceramics, [77][78][79] glasses, 80 organicinorganic hybrids, 81,82 and polymers. 83,84 The real part of AC-conductivity (σ') can also be described by the random free-energy barrier model proposed by Dyre.…”

Section: T a B L Ementioning

confidence: 79%

Molecular dynamics and conduction mechanism of poly(vinyl chloride‐co‐vinyl acetate‐co‐2‐hydroxypropyl acrylate) terpolymer containing ionic liquid

Elmahdy

Aldhafeeri

Ahmed

et al. 2022

Polymers for Advanced Techs

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Dielectric spectroscopy (DS) measurements were performed to probe the segmental dynamics and ion mobility of poly(vinyl chloride‐co‐vinyl acetate‐co‐2‐hydroxypropyl acrylate) terpolymer dopped with different amounts of tetrabutylammonium tetrafluoroborate ([TBA] [BF4]) ionic liquid (IL). Differential scanning calorimetry (DSC) was also employed to trace the change in the glass transition temperature (Tg) at different loads of IL. The DSC measurements revealed a remarkable reduction in the PVVH Tg from 344 to 310 K just by adding 20 wt% of IL. The DS measurements revealed three relaxation processes named α, β1, and β2. The α‐process is related to the segmental motion of PVVH while the β1 and β2 are due to the restricted local dynamics of side chains. The segmental relaxation times (α‐relaxation) speed up with increasing the concentration of IL due to the plasticization effect of IL on polymer chains. The temperature dependence of α‐relaxation follows the Vogel‐Fulcher‐Tammann (VFT) relation with dynamic glass transition between 323 and 294 K in agreement with the DSC measurements. The β1 and β2‐relaxations have an Arrhenius temperature dependence. The temperature dependence of ionic conductivity obeys the VFT behavior indicating the coupling between the segmental motion of PVVH chains and ion transport. Polaronic tunneling is the predominant conduction mechanism in PVVH and its composites. The specific capacitance increases with increasing both the temperature and IL concentration.

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“…Schott D263M borosilicate glass was selected as the control base-substrate for this study as does not possess optical, physical, or chemical properties that could impact the QD emission. [19][20][21] The thickness of these layers was calculated from the calibrated deposition rates of the sputter machine for each metal. The substrates were exposed to air to permit oxidation of the metals.…”

Section: Methodsmentioning

confidence: 99%

Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

Patty

Sadeghi

Campbell

et al. 2014

Journal of Applied Physics

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We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.

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AC conductivity and dielectric properties of SiO2–Na2O–B2O3–Gd2O3 glasses

Cited by 66 publications

References 38 publications

The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework

The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework

Molecular dynamics and conduction mechanism of poly(vinyl chloride‐co‐vinyl acetate‐co‐2‐hydroxypropyl acrylate) terpolymer containing ionic liquid

Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

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AC conductivity and dielectric properties of SiO2–Na2O–B2O3–Gd2O3 glasses

Cited by 66 publications

References 38 publications

The dielectric relaxation behavior induced by sodium migration in the Na2CoSiO4 structure within a three-dimensional Co–O–Si framework

The dielectric relaxation behavior induced by sodium migration in the Na2CoSiO4 structure within a three-dimensional Co–O–Si framework

Molecular dynamics and conduction mechanism of poly(vinyl chloride‐co‐vinyl acetate‐co‐2‐hydroxypropyl acrylate) terpolymer containing ionic liquid

Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

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The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework

The dielectric relaxation behavior induced by sodium migration in the Na₂CoSiO₄ structure within a three-dimensional Co–O–Si framework