Ionic conductivity enhancement in Gd2Zr2O7 pyrochlore by Nd doping

2008 ◽  
Vol 23 (4) ◽  
pp. 911-916 ◽  
Author(s):  
B.P. Mandal ◽  
S.K. Deshpande ◽  
A.K. Tyagi
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Preexponential Factor ◽  
Dc Conductivity ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Conductivity Enhancement ◽  
Mobile Species ◽  
Oxygen Ion ◽  
Mobile Ions

The pyrochlore compositions Gd2–yNdyZr2O7 (y = 0.0, 0.1, 0.4, 0.6, 1.0, 1.4, 1.6, and 2.0) were synthesized, and their ionic conductivity was determined (100 Hz–15 MHz, 622–696 K). The direct-current (dc) conductivity (σdc) varies upon Nd substitution at the Gd site, and a peaking effect in σdc was observed around y = 1.0. This indicates that a significant increase in conductivity can be obtained at moderately high temperatures by suitable doping at the Gd site with isovalent rare-earth ions like Nd. The extent of oxygen ion disorder determined from x-ray diffraction was found to decrease with increasing Nd content. The dc conductivity obeys the Arrhenius relation σdcT = σ0 exp(−E/kBT). The activation energy E and the preexponential factor σ0, which is a measure of the concentration of the mobile species, increase while going from the ordered Nd2Zr2O7 to the least ordered Gd2Zr2O7. These two processes presumably lead to the peaking of σdc at an intermediate Nd content. Our results also suggest that the cooperative motion of mobile ions does not contribute much to the increase in activation energy in this compound.

scholarly journals Natural Inspired Carboxymethyl Cellulose (CMC) Doped with Ammonium Carbonate (AC) as Biopolymer Electrolyte

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2487
Author(s):  
Mohd Ibnu Haikal Ahmad Sohaimy ◽  
Mohd Ikmar Nizam Mohamad Isa
Keyword(s):  
Ionic Conductivity ◽  
Carboxymethyl Cellulose ◽  
Ammonium Carbonate ◽  
Ionic Mobility ◽  
Core Material ◽  
X Ray Diffraction ◽  
Electrolyte System ◽  
Conductivity Enhancement ◽  
Biopolymer Electrolyte ◽  
Mobile Ions

Green and safer materials in energy storage technology are important right now due to increased consumption. In this study, a biopolymer electrolyte inspired from natural materials was developed by using carboxymethyl cellulose (CMC) as the core material and doped with varied ammonium carbonate (AC) composition. X-ray diffraction (XRD) shows the prepared CMC-AC electrolyte films exhibited low crystallinity content, Xc (~30%) for sample AC7. A specific wavenumber range between 900–1200 cm−1 and 1500–1800 cm−1 was emphasized in Fourier transform infrared (FTIR) testing, as this is the most probable interaction to occur. The highest ionic conductivity, σ of the electrolyte system achieved was 7.71 × 10−6 Scm−1 and appeared greatly dependent on ionic mobility, µ and diffusion coefficient, D. The number of mobile ions, η, increased up to the highest conducting sample (AC7) but it became less prominent at higher AC composition. The transference measurement, tion showed that the electrolyte system was predominantly ionic with sample AC7 having the highest value (tion = 0.98). Further assessment also proved that the H+ ion was the main conducting species in the CMC-AC electrolyte system, which presumably was due to protonation of ammonium salt onto the complexes site and contributed to the overall ionic conductivity enhancement.

Synthesis and Ionic Conductivity of MAlSi3O8 (M = Li, Na, K)

2018 ◽  
Vol 790 ◽  
pp. 9-14
Author(s):  
Shin Ichi Furusawa ◽  
Yohei Minami
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Ionic Radius ◽  
Ionic Conduction ◽  
Solid Phase ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

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.

Sulfur doped Li1.3Al0.3Ti1.7(PO4)3 solid electrolytes with enhanced ionic conductivity and a reduced activation energy barrier

2020 ◽  
Vol 22 (30) ◽  
pp. 17221-17228
Author(s):  
Abdulkadir Kızılaslan ◽  
Mine Kırkbınar ◽  
Tugrul Cetinkaya ◽  
Hatem Akbulut
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Energy Barrier ◽  
Solid Electrolytes ◽  
Activation Energy Barrier ◽  
Conductivity Enhancement

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

Effective energy landscapes for mobile ions in solid electrolytes

2004 ◽  
Vol 835 ◽  
Author(s):  
Stefan Adams
Keyword(s):  
Activation Energy ◽  
Ion Transport ◽  
Solid Electrolytes ◽  
Transport Mechanism ◽  
Bond Valence ◽  
Trivalent Cation ◽  
Effective Energy ◽  
Energy Landscapes ◽  
Mobile Species ◽  
Mobile Ions

ABSTRACTBond valence mismatch landscapes may serve as simple models of the effective energy landscapes for mobile ions in solid electrolytes. Thereby they provide a tool to identify the ion transport mechanism and allow to predict the activation energy of the ionic conduction. Accounting for the mass dependence of the conversion from the BV mismatch into an activation energy scale yields a correlation that holds for different types of mobile cations. While in most cases the analysis of bond valence mismatch landscapes is consistent with the ion transport mechanism derived from experimental or other computational evidence, the presumed prototype of trivalent cation conductors Sc2(WO4)3 is discussed as an example, where the BV analysis of transport pathways suggests that the interpretation of previous experimental investigations has to be reconsidered. Both bond valence calculations and molecular dynamics simulations suggests that the most probable mobile species in stoichiometric Sc2(WO4)3 is neither Sc3+ nor individual O2- but the complex divalent anion WO42-.

scholarly journals Electrical Conductivity Enhancement of V2O5-P2O5-Bi2O3 Glasses by Nanocrystallization

2021 ◽  
Author(s):  
F. A. Ibrahim
Keyword(s):  
Electrical Conductivity ◽  
Glass Ceramic ◽  
Glass Structure ◽  
Dc Conductivity ◽  
Glass System ◽  
X Ray Diffraction ◽  
Conductivity Enhancement ◽  
Average Grain Size ◽  
Structural And Electrical Properties ◽  
Xrd Patterns

AbstractThe structural and electrical properties of the xP2O5-(40 − x) Bi2O3-60V2O5 (0 ≤ x ≤ 20) glass system have been investigated. The samples were prepared by the conventional melt-quenching technique. X-ray diffraction (XRD) patterns confirmed the amorphous nature of the present glasses. Nanocrystalline grains were found due to the annealing of the glass samples under study. Nanocrystals with an average grain size of 22 nm were implanted in the glass structure and estimated from the XRD patterns of the glass–ceramic samples. DC conductivity of the glass system has been determined in the temperature range 300–500 K. It was found that the general behavior of electrical conductivity was similar for all the glass compositions and found to decrease with increasing phosphate content. The electrical conductivity of the glass–ceramic nanocrystals obtained by annealing at crystallization temperature (Tc) was much higher than the initial glass. The activation energy (W) was enhanced by annealing and was obtained from plots of temperature-dependent DC conductivity, and found to be 0.23–0.31 eV for glasses and 0.19–0.23 eV for the glass–ceramic nanocrystals.

Cation Ordering in Brownmillerite-Perovskite Intergrowth Structures

1992 ◽  
Vol 293 ◽  
Author(s):  
Julie K. Thomas ◽  
Wendy E. Krause ◽  
Hans-Conrad Zur Loye
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Cation Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Ion Conductivity ◽  
Oxygen Ion ◽  
Cubic Structure ◽  
Intergrowth Structures ◽  
Cation Arrangement

AbstractBrownmillerite-perovskite intergrowths of the type m(A2B2O5)*n(ABO3), where m = 1 and n = 1, were investigated with respect to cation ordering. It was found that Sr31n2ZrO8, Sr31n2HfO8, Ba3Sc2TiO8 and Ba31n2TiO8 form in a disordered cubic structure, while Sr3Sc2ZrO8 and Ba3Sc2ZrO8 form an ordered cation arrangement. The Arrhenius plots of the oxygen ion conductivity of Ba3Sc2ZrO8, Sr31n2HfO8, and Ba31n2TiO8 contain discontinuities that appear to be caused by an oxygen vacancy order-disorder transition. High temperature powder-X ray diffraction did not show any evidence for cation ordering that might otherwise have created the changes in activation energy in the conductivity plots.

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier
Keyword(s):  
Ionic Conductivity ◽  
Vacancy Concentration ◽  
Sodium Ion ◽  
High Ionic Conductivity ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid State Batteries ◽  
Ion Conducting ◽  
Very High

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>

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