Calculation of Activation Energy of Ionic Conductivity in Silica Glasses by Classical Methods

1954 ◽  
Vol 37 (12) ◽  
pp. 573-580 ◽  
Author(s):  
O. L. ANDERSON ◽  
D. A. STUART
Cerâmica ◽  
2006 ◽  
Vol 52 (321) ◽  
pp. 22-30 ◽  
Author(s):  
M. L. F. Nascimento ◽  
E. Nascimento ◽  
W. M. Pontuschka ◽  
M. Matsuoka ◽  
S. Watanabe

We collected and analyzed literature data on ionic conductivity sigma and activation energy E A in the binary sodium silicate system in a wide composition range. The Anderson and Stuart model has been considered to describe the decreasing tendency of activation energy E A with alkali concentration in this system. In this analysis were considered experimental parameters, such as shear modulus G and relative dielectric permittivity epsilon. A general conductivity rule is found in 194 of 205 glasses, when one plots log sigma vs. E A/kB T, where kB is the Boltzmann constant and T is the absolute temperature. This fact means that the arrhenian relation has universal uniqueness of form sigma = sigma (E A,T) in wide Na2O composition range. The results also show that there is strong correlation by more than 19 orders of magnitude on conductivity with E A/kBT. An explanation for this behavior links ionic conductivity and microscopic structure. The problem of phase separation in this system is also considered.


2018 ◽  
Vol 790 ◽  
pp. 3-8 ◽  
Author(s):  
Shin Ichi Furusawa ◽  
Tomosato Ida

Tensile stress was applied to β-AgI thin film prepared on a polyethylene terephthalate film, and the ion conduction response in the direction of the tensile extension was investigated. The ionic conductivity of the β-AgI thin film decreases and the activation energy for ionic conduction increases with increasing extension ratio. This behaviour is attributed to the modulation of the crystal framework by the extension of the AgI thin film.


2018 ◽  
Vol 790 ◽  
pp. 9-14
Author(s):  
Shin Ichi Furusawa ◽  
Yohei Minami

MAlSi3O8 (M = Li, Na, K) was synthesized by solid-phase reaction at 1000 °C using M2CO3 (M = Li, Na, K), Al2O3, and SiO2 as the starting materials, and its ionic conduction was studied in the temperature range 475–800 K. It was confirmed from powder X-ray diffraction profiles that the crystalline phases of the prepared MAlSi3O8 were the same as those of orthoclase. Moreover, the ionic conductivity of NaAlSi3O8 was about 10 times higher than that of LiAlSi3O8 and KAlSi3O8. The activation energies for ionic conduction were estimated to be in the range of 0.70–0.77 eV, with NaAlSi3O8 exhibiting the lowest activation energy. The result suggests that the magnitude of the activation energy cannot be determined only from the ionic radius.


2020 ◽  
Vol 22 (30) ◽  
pp. 17221-17228
Author(s):  
Abdulkadir Kızılaslan ◽  
Mine Kırkbınar ◽  
Tugrul Cetinkaya ◽  
Hatem Akbulut

The mechanism of the ionic conductivity enhancement in sulfur-doped Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid electrolytes.


1990 ◽  
Vol 210 ◽  
Author(s):  
Cui Wanqiu ◽  
Shen Zhiqi ◽  
Zhou Debao

AbstractThe multicrystal multiphase ceramics material. Li2Mo2Wx06, with high conductivity is prepared. By XPD, EDX graph, IR and ESR spectra, it's determined that the samples are composed of two phases.Li2MO1-xWx04 and MoO2. The electrical properties are studied by AC admittance bridge and comptex impedance cpectroscopy. The ionic conductivity increases and conducted activation energy decreases with the tungsten content increasing. The micro-structure model. and the ionic conducted mechanism are given in this paper.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6404
Author(s):  
Yongqing Wang ◽  
Bo An ◽  
Ke Wang ◽  
Yan Cao ◽  
Fan Gao

To identify critical parameters upon variable operational temperatures in a planar SOFC, an experimentally agreeable model was established. The significance of temperature effect on the performance of SOFC components was investigated, and the effect of activation energy during the development of intermediate electrode materials was evaluated. It is found the ionic conductivity of electrolytes is identified to be unavoidably concerned in the development of the intermediate-temperature SOFC. The drop of the ionic conductivity of the electrolyte decreases the overall current density 63% and 80% at temperatures reducing to 700 °C and 650 °C from 800 °C. However, there exists a critical value on the defined ratio between the electric resistance of the electrolyte in the overall internal resistance of SOFC, above which the further increase in the ionic conductivity would not significantly improve the performance. The lower the operational temperature, the higher critical ratio of the electrical resistance in the overall internal resistance of the cell. The minimal decrease in the activation energy during the development of intermediate electrode materials can significantly enhance the overall performance. Considering the development trend toward the intermediate temperature SOFC, advanced electrode material with the decreased activation energy should be primarily focused. The result provides a guidance reference for developing SOFC with the operational temperature toward the intermediate temperature.


2020 ◽  
pp. 089270572093075
Author(s):  
Jitender Paul Sharma ◽  
Neelam Guleria

In the present work, nanocomposite polymer electrolyte films were prepared by solution casting technique using nanosized fumed silica to polyethylene oxide (PEO)-based polymer electrolytes containing ammonium bifluoride (NH4HF2). The ionic conductivity of 1.19 × 10−5 S cm−1 has been observed at room temperature (25°C) for 3 wt% fumed silica in PEO-10 wt% NH4HF2 polymer electrolytes after which the conductivity was observed to decrease. Furthermore, the addition of high dielectric constant plasticizer propylene carbonate (PC) in the optimized composition of nanocomposite polymer electrolytes has increased the number of charge carriers by the large dissolution of ionic salt, amorphous content, and hence the ionic conductivity. Maximum ionic conductivity obtained at room temperature was found to be 1.55 × 10−4 S cm−1 in the case of PEO-10 wt% NH4HF2-3 wt% fumed silica-0.3 (ml) PC polymer electrolytes which is five orders of magnitude higher than that of the polymer host material. Temperature-dependent ionic conductivity, activation energy, and dielectric constant studies have been described for all the compositions of polymer electrolytes. Ionic conductivity and dielectric constant studies were determined from impedance data. Polymer electrolytes containing both fumed silica and PC highlight that there is no phase transition in the polymer electrolyte and temperature dependence of ionic conductivity in the temperature range is of almost Arrhenius type. The lowest activation energy value for the highest conducting polymer electrolyte was found to be 0.172 eV. Change in melting temperature, % crystallinity ( χ c), and mechanical properties have also been observed in polymer electrolytes containing fumed silica as well as PC as studied by Differential Scanning Calorimetry/Thermogravimetric Analysis (DSC/TGA) and universal testing machine, respectively.


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