Research on the electrochemistry of oxygen ion conductors in the former Soviet Union

Хартон, В.В.; Naumovich, E.N.; Yaremchenko, A.A.; Marques, F.M.B.

doi:10.1007/s100080000141

Cited by 128 publications

(108 citation statements)

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“…Dilatometric studies showed that thermal expansion at 300-1173 K can be described with a standard linear model for all studied materials (Fig.3) (Fig.3), as observed for oxygen ion-conducting solid electrolytes [16]. The phenomenological theory of ionic transport [17] qualitatively explains this behavior by the increasing mobility of ionic defects with thermal expansion of the crystal.…”

Section: Thermal Expansionsupporting

confidence: 53%

Síntesis y caracterización del conductor catiónico de sodio Nax(MyL1-y)O2 (M = Ni2+, Fe3+; L = Ti4+, Sb5+)

Smirnova¹,

Хартон²,

Marques³

2004

Bol. Soc. Esp. Ceram. Vidr.

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The Na + -conducting ceramics of layered Na 0.8 Ni 0.4 Ti 0.6 O 2 , Na 0.8 Fe 0.8 Ti 0.2 O 2 , Na 0.8 Ni 0.6 Sb 0.4 O 2 (structural type O3) and Na 0.68 Ni 0.34 Ti 0.66 O 2 (P2 type) with density higher than 91% were prepared via the standard solid-state synthesis route and characterized by the impedance spectroscopy, thermal analysis, scanning electron microscopy, structure refinement using X-ray powder diffraction data, measurements of Na + concentration cell e.m.f., and dilatometry. The conductivity of antimonate Na 0.8 Ni 0.6 Sb 0.4 O 2 , synthesized first time, was found lower than that of isostructural Na 0.8 Ni 0.4 Ti 0.6 O 2 due to larger ion jump distance between Na + sites. At temperatures above 420 K, transport properties of sodium cationconducting materials are essentially independent of partial water vapor pressure. In the low-temperature range, the conductivity reversibly increases with water vapor pressure varied in the range from approximately 0 (dry air) up to 0.46 atm. The sensitivity to air humidity is influenced by the ceramic microstructure, being favored by increasing boundary area. The average thermal expansion coefficients of layered materials at 300-1173 K are in the range (13.7-16.0)×10 (tipo P2) con densidad mayor del 91%. Las vía de preparación fu la ruta de estandard de síntesis en estado sólido. Las composiciones se caracterizaron mediante espectroscopía de impedancia, análisis térmico, microscopía electrónica de barrido, refinamiento de la estructura usando datos de difracción de rayos X en polvo, medidas de concentración de Na + , f.e.m. de la célula y dilatometría. La conductividad del antimoniate, sintetizado por primera vez, Na 0.8 Ni 0.6 Sb 0.4 O 2 , era menor que la del compuesto isoestructural Na 0.8 Ni 0.4 Ti 0.6 O 2 debido a la mayor distancia de salto iónico entre las posiciones de Na + . A temperaturas por encima de 420 K, las propiedades de transporte de los materiales conductores que contienen cations sodio son esencialmente independientes de la presión parcial de vapor de agua. En el intervalo de baja temperatura, la conductividad aumenta reversiblemente con la presión de vapor de agua variando en un intervalo de aproximadamente 0 (aire seco) hasta 0.46 atm. La sensibilidad a la humedad del aire está influída por la microestructura de la cerámica, estando favorecida al aumentar el área de borde. Los coeficientes de dilatación térmica medios de los materiales laminares entre 300 y 1173 K están en el intervalo (13.7-16.0)×10 -6 K -1 .Palabras clave: conductor con cationes sodio, espectroscopia de impedancia, humedad del aire, dilatación térmica, microestructura cerámica.

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Section: Thermal Expansionsupporting

confidence: 53%

Síntesis y caracterización del conductor catiónico de sodio Nax(MyL1-y)O2 (M = Ni2+, Fe3+; L = Ti4+, Sb5+)

Smirnova¹,

Хартон²,

Marques³

2004

Bol. Soc. Esp. Ceram. Vidr.

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“…Numerous literature data (for instance, Ref. [31] and references therein) suggest a negligible dissolution of Ce 4 + ions in the lattice of perovskite phases, where the A sublattice is mainly occupied by lanthanum and the B sites contain tran- [31,32]. Diffusion of the cations constituting LSFC lattice into the ceria-based phase may lead to an imbalance between A-site and B-site cations in the perovskite structure, which can result in either A-site cation deficiency of the perovskite or segregation of iron and cobalt oxide phases.…”

Section: Characterization Of the Composite Ceramicsmentioning

confidence: 99%

“…However, the dual-phase membranes show, as a rule, significantly lower permeation fluxes as compared to single-phase mixed conductors. The only exception refers to the composites of stabilized y-Bi 2 O 3 and metallic silver [15,16], which have significant oxygen permeability at 870 to 1100 K but may be unstable due to decomposition of the stabilized y-Bi 2 O 3 phase at temperatures below 900 -920 K as well as reactivity of bismuth oxide with silver at T>850 K [17]. Therefore, further developments of the membrane materials are still necessary.…”

Section: Introductionmentioning

confidence: 99%

Oxygen transport in Ce0.8Gd0.2O2−-based composite membranes

et al. 2003

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Gadolinia-doped ceria electrolyte Ce 0.8 Gd 0.2 O 2 À d (CGO) and perovskite-type mixed conductor La 0.8 Sr 0.2 Fe 0.8 Co 0.2 O 3 À d (LSFC), having compatible thermal expansion coefficients (TECs), were combined in dual-phase ceramic membranes for oxygen separation. Oxygen permeability of both LSFC and composite LSFC/CGO membranes at 970 -1220 K was found to be limited by the bulk ambipolar conductivity. LSFC exhibits a relatively low ionic conductivity and high activation energy for ionic transport ( f 200 kJ/mol) in comparison with doped ceria. As a result, oxygen permeation through LSFC/CGO composite membranes, containing similar volume fractions of the phases, is determined by the ionic transport in CGO. The permeation fluxes through LSFC/CGO and La 0.7 Sr 0.3 MnO 3 À d /Ce 0.8 Gd 0.2 O 2 À d (LSM/CGO) composites have comparable values. An increase in the p-type electronic conductivity of ceria in oxidizing conditions, which can be achieved by co-doping with variable-valence metal cations, such as Pr, leads to a greater permeability. The oxygen ionic conductivity of the composites consisting of CGO and perovskite oxides depends strongly of processing conditions, decreasing with interdiffusion of the phase components, particularly lanthanum and strontium cations from the perovskite into the CGO phase. D

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“…This trend is often observed among perovskites with 3d-metals, where an increase of conductivity occurs from Cr-, Mn-and Fe-to Co-containing perovskites and then decreases to Ni-containing ones. Thus, the conductivity of LaCrO 3 is 0.34 S/cm (970 K), LaMnO 3 -81 S/cm (1000 K); LaFeO 3 -0.1 S/cm (800 K); LaCoO 3 -1000 S/cm (800 K); LaNiO 3 -410 S/cm (900 K) [30][31][32]. The thermal expansion for all samples exhibits a low and a high temperature part, at To673 K and T4673 K, respectively.…”

Section: Crystal Structure Of Srmentioning

confidence: 99%

Synthesis and characterization of perovskite-type SrxY1−xFeO3−δ (0.63≤x<1.0) and Sr0.75Y0.25Fe1−yMyO3−δ (M=Cr, Mn, Ni), (y=0.2, 0.33, 0.5)

Biendicho

Shafeie

Frenck

et al. 2013

Journal of Solid State Chemistry

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Research on the electrochemistry of oxygen ion conductors in the former Soviet Union

Cited by 128 publications

References 0 publications

Síntesis y caracterización del conductor catiónico de sodio Na<sub>x</sub>(M<sub>y</sub>L<sub>1-y</sub>)O<sub>2</sub> (M = Ni<sup>2+</sup>, Fe<sup>3+</sup>; L = Ti<sup>4+</sup>, Sb<sup>5+</sup>)

Síntesis y caracterización del conductor catiónico de sodio Na<sub>x</sub>(M<sub>y</sub>L<sub>1-y</sub>)O<sub>2</sub> (M = Ni<sup>2+</sup>, Fe<sup>3+</sup>; L = Ti<sup>4+</sup>, Sb<sup>5+</sup>)

Oxygen transport in Ce0.8Gd0.2O2−-based composite membranes

Synthesis and characterization of perovskite-type SrxY1−xFeO3−δ (0.63≤x<1.0) and Sr0.75Y0.25Fe1−yMyO3−δ (M=Cr, Mn, Ni), (y=0.2, 0.33, 0.5)

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