Nature of conductivity of Perovskites La1 − x Sr x ScO3 − α (x = 0.01–0.15) under oxidative and reducing conditions

Stroeva, А. Yu.; Горелов, В. П.

doi:10.1134/s1023193512110158

Cited by 32 publications

(5 citation statements)

References 9 publications

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“…Acceptor-doped materials based on the LaScO 3 are mixed ion-hole conductors in oxidizing conditions [9,10,11,12,13,14]. Proton and oxygen-ion defects are formed according to Equations (2) and (3), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In reducing atmospheres, these materials are ionic conductors [9,11,14]; therefore, the concentration of holes and electrons is neglectable and the electroneutrality condition can be transformed to 2false[VO••false]+false[OHO•false]=false[CaLa/false].…”

Section: Resultsmentioning

confidence: 99%

“…The transport properties of La 0.9 Sr 0.1 Sc 0.9 Mg 0.1 O 3−α [10,11]; LaSc 1−x Mg x O 3−α [12], La 1−x Sr x ScO 3−α [9,10,13,14,15,16] have been investigated in detail. Fujii et al [12] reported the conductivities of La 1−x Ca x ScO 3−α .…”

Section: Introductionmentioning

confidence: 99%

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Water Uptake and Transport Properties of La1−xCaxScO3−α Proton-Conducting Oxides

et al. 2019

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In this study, oxide materials La1−xCaxScO3−α (x = 0.03, 0.05 and 0.10) were synthesized by the citric-nitrate combustion method. Single-phase solid solutions were obtained in the case of calcium content x = 0.03 and 0.05, whereas a calcium-enriched impurity phase was found at x = 0.10. Water uptake and release were studied by means of thermogravimetric analysis, thermodesorption spectroscopy and dilatometry. It was shown that lower calcium content in the main phase leads to a decrease in the water uptake. Conductivity was measured by four-probe direct current (DC) and two-probe ascension current (AC) methods at different temperatures, pO2 and pH2O. The effects of phase composition, microstructure and defect structure on electrical conductivity, as well as correlation between conductivity and water uptake experiments, were discussed. The contribution of ionic conductivity of La1−xCaxScO3−α rises with decreasing temperature and increasing humidity. The domination of proton conductivity at temperatures below 500 °C under oxidizing and reducing atmospheres is exhibited. Water uptake and release as well as transport properties of La1−xCaxScO3−α are compared with the properties of similar proton electrolytes, La1−xSrxScO3−α, and the possible reasons for their differences were discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Water Uptake and Transport Properties of La1−xCaxScO3−α Proton-Conducting Oxides

et al. 2019

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“…The high proton conductivity was attributed to the increased number of mobile protons due to the high concentration of oxygen vacancy at x = 0.2. Extensive studies on crystal structure, electrical conductivity, water incorporation, oxygen and hydrogen diffusivities of lanthanumstrontium scandate were performed [4][5][6]. Unlike acceptor-doped Ba(Zr,Ce)O 3 materials, La 1−x Sr x ScO 3−δ (LSS) oxides demonstrate high stability and protonic conductivity not only in water-containing, but also in reduced and carbon-containing atmospheres [7,8].…”

Section: Introductionmentioning

confidence: 99%

Sr Doping and Oxygen Vacancy Formation in La1−xSrxScO3−δ Solid Solutions: Computational Modelling

et al. 2022

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Sr-doped lanthanum scandate La1−xSrxScO3−δ (LSS) is a promising perovskite-type material for electrochemical applications such as proton conductors. Oxygen vacancy is a common defect in ABO3-type perovskites. It controls ion transport as well as proton uptake. The energetic, structural, and electronic properties of oxygen vacancy in LSS are studied deploying the DFT method with meta-GGA functional. The vacancy formation energies in LSS were calculated for various Sr concentrations. Unlike other perovskites, in this material, the electrons are trapped at the oxygen vacancy site (the F-type centres, common in ionic oxides like MgO and Al2O3) rather than localised on the nearest to the vacancy B-cations. The process of oxygen vacancy formation is considered relative to Sr concentration x and oxygen nonstoichiometry factor δ. Three primary regimes are discussed: (I) localized at the vacancy electrons, x/δ < 2, (II) electron charge balanced system, x/δ = 2, and (III) delocalized electron holes, x/δ > 2. For x/δ ≥ 2 oxygen vacancy formation energy reaches the saturation level of ~3.5 eV, which is potentially beneficial for the proton uptake.

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“…Sr-doped lanthanum scandate—La 1− x Sr x ScO 3− δ (LSS)—is a well-known proton conductor used in protonic–ceramic fuel cells (PCFC) [ 1 ]. Crystalline structure, electrical conductivity, water incorporation, and oxygen and hydrogen diffusivities of lanthanum-strontium scandate were studied in [ 2 , 3 , 4 , 5 ].…”

Section: Introductionmentioning

confidence: 99%

Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study

et al. 2022

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The atomic structure of antiphase boundaries in Sr-doped lanthanum scandate (La1−xSrxScO3−δ) perovskite, promising as the proton conductor, was modelled by means of DFT method. Two structural types of interfaces formed by structural octahedral coupling were constructed: edge- and face-shared. The energetic stability of these two interfaces was investigated. The mechanisms of oxygen vacancy formation and migration in both types of interfaces were modelled. It was shown that both interfaces are structurally stable and facilitate oxygen ionic migration. Oxygen vacancy formation energy in interfaces is lower than that in the regular structure, which favours the oxygen vacancy segregation within such interfaces. The calculated energy profile suggests that both types of interfaces are advantageous for oxygen ion migration in the material.

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Nature of conductivity of Perovskites La1 − x Sr x ScO3 − α (x = 0.01–0.15) under oxidative and reducing conditions

Cited by 32 publications

References 9 publications

Water Uptake and Transport Properties of La1−xCaxScO3−α Proton-Conducting Oxides

Water Uptake and Transport Properties of La1−xCaxScO3−α Proton-Conducting Oxides

Sr Doping and Oxygen Vacancy Formation in La1−xSrxScO3−δ Solid Solutions: Computational Modelling

Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study

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