scholarly journals Crossover to nearly constant loss in ac conductivity of highly disordered pyrochlore-type ionic conductors

2010 ◽  
Vol 82 (17) ◽  
Author(s):  
M. R. Díaz-Guillén ◽  
J. A. Díaz-Guillén ◽  
A. F. Fuentes ◽  
J. Santamaría ◽  
C. León
Keyword(s):  
Ac Conductivity ◽  
Ionic Conductors ◽  
Pyrochlore Type ◽  
Nearly Constant Loss

Composition dependence of the dispersive nature of the ac conductivity in ionic conductors Gd2Ti2−yZryO7 and Li0.5−xNaxLa0.5TiO3

2006 ◽  
Vol 352 (42-49) ◽  
pp. 5141-5146 ◽  
Author(s):  
J. García-Barriocanal ◽  
K.J. Moreno ◽  
A.F. Fuentes ◽  
J. Santamaría ◽  
C. León
Keyword(s):  
Ac Conductivity ◽  
Composition Dependence ◽  
Ionic Conductors ◽  
Dispersive Nature

Origin and properties of the nearly constant loss in crystalline and glassy ionic conductors

2002 ◽  
Vol 307-310 ◽  
pp. 1024-1030 ◽  
Author(s):  
A Rivera ◽  
J Santamarı́a ◽  
C León ◽  
J Sanz ◽  
C.P.E Varsamis ◽  
...  
Keyword(s):  
Ionic Conductors ◽  
Nearly Constant Loss

scholarly journals Impact of Praseodymia Additions and Firing Conditions on Structural and Electrical Transport Properties of 5 mol.% Yttria Partially Stabilized Zirconia (5YSZ)

2021 ◽  
Vol 11 (13) ◽  
pp. 5939
Author(s):  
Alejandro Natoli ◽  
Jorge R. Frade ◽  
Aleksandr Bamburov ◽  
Agnieszka Żurawska ◽  
Aleksey Yaremchenko
Keyword(s):  
Electrical Transport ◽  
Pyrochlore Phase ◽  
Nominal Composition ◽  
Ionic Conductors ◽  
Electrical Transport Properties ◽  
Praseodymium Oxide ◽  
Total Electrical Conductivity ◽  
Thermal Expansion Coefficients ◽  
Pyrochlore Type ◽  
P Type

Ceramics samples with the nominal composition [(ZrO2)0.95(Y2O3)0.05]1-x[PrOy]x and praseodymia contents of x = 0.05–0.15 were prepared by the direct firing of compacted 5YSZ + PrOy mixtures at 1450–1550 °C for 1–9 h and characterized for prospective applicability in reversible solid oxide cells. XRD and SEM/EDS analysis revealed that the dissolution of praseodymium oxide in 5YSZ occurs via the formation of pyrochlore-type Pr2Zr2O7 intermediate. Increasing PrOy additions results in a larger fraction of low-conducting pyrochlore phase and larger porosity, which limit the total electrical conductivity to 2.0–4.6 S/m at 900 °C and 0.28–0.68 S/m at 700 °C in air. A longer time and higher temperature of firing promotes the phase and microstructural homogenization of the ceramics but with comparatively low effect on density and conductivity. High-temperature processing leads to the prevailing 3+ oxidation state of praseodymium cations in fluorite and pyrochlore structures. The fraction of Pr4+ at 600–1000 °C in air is ≤2% and is nearly independent of temperature. 5YSZ ceramics with praseodymia additions remain predominantly oxygen ionic conductors, with p-type electronic contribution increasing with Pr content but not exceeding 2% for x = 0.15 at 700–900 °C. The average thermal expansion coefficients of prepared ceramics are in the range of 10.4–10.7 ppm/K.

scholarly journals Electrode and Electrolyte Materials From Atomistic Simulations: Properties of LixFEPO4 Electrode and Zircon-Based Ionic Conductors

2021 ◽  
Vol 9 ◽  
Author(s):  
Piotr M. Kowalski ◽  
Zhengda He ◽  
Oskar Cheong
Keyword(s):  
Energy Storage ◽  
Ceramic Materials ◽  
Yttria Stabilized Zirconia ◽  
Miscibility Gap ◽  
Ambient Conditions ◽  
Ionic Conductors ◽  
Stabilized Zirconia ◽  
Energy Storage Devices ◽  
Energy Applications ◽  
Pyrochlore Type

LixFePO4 orthophosphates and fluorite- and pyrochlore-type zirconate materials are widely considered as functional compounds in energy storage devices, either as electrode or solid state electrolyte. These ceramic materials show enhanced cation exchange and anion conductivity properties that makes them attractive for various energy applications. In this contribution we discuss thermodynamic properties of LixFePO4 and yttria-stabilized zirconia compounds, including formation enthalpies, stability, and solubility limits. We found that at ambient conditions LixFePO4 has a large miscibility gap, which is consistent with existing experimental evidence. We show that cubic zirconia becomes stabilized with Y content of ~8%, which is in line with experimental observations. The computed activation energy of 0.92eV and ionic conductivity for oxygen diffusion in yttria-stabilized zirconia are also in line with the measured data, which shows that atomistic modeling can be applied for accurate prediction of key materials properties. We discuss these results with the existing simulation-based data on these materials produced by our group over the last decade. Last, but not least, we discuss similarities of the considered compounds in considering them as materials for energy storage and radiation damage resistant matrices for immobilization of radionuclides.

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