Phase relations, chemical diffusion and electrical conductivity in pure and doped Sr4Fe6O13 mixed conductor materials

Bredesen, Rune; Norby, Truls; Bardal, A.; Lynum, Vibeke

doi:10.1016/s0167-2738(00)00382-9

Cited by 34 publications

(19 citation statements)

References 8 publications

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“…Solid solution of La in Sr 4 Fe 6 O 13+δ demands an increase in δ due to the higher valence of La 3+ compared to Sr 2+ , but Sr 4 Fe 6 O 13±δ has been reported to be essentially stoichiometric at 1000°C 19 . A small δ infers a low solubility in line with observations reported by Bredesen et al 20 . Higher temperature will further reduce the solubility of La 3+ in Sr 4 Fe 6 O 13±δ .…”

Section: Resultssupporting

confidence: 87%

Phase Relations In The Pseudo‐Ternary System La₂O₃–SrO–Fe₂O₃

Fossdal

Einarsrud

Grande

2005

Journal of the American Ceramic Society

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The phase relations in the pseudo‐ternary system La2O3–SrO–Fe2O3 have been investigated in air. Isothermal sections at 1100° and 1300°C are presented based on X‐ray diffraction and thermal analysis of annealed samples. Extended solid solubility was observed for the compounds Srn+1−vLavFenO3n+1−δ (n=1, 2, 3, and ∞) and Sr1−xLaxFe12O19, while only limited solubility of La in Sr4−zLazFe6O13±δ was observed. At high Fe2O3 content, a liquid with low La2O3 content was stable at 1300°C.

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Section: Resultssupporting

confidence: 87%

Phase Relations In The Pseudo‐Ternary System La₂O₃–SrO–Fe₂O₃

Fossdal

Einarsrud

Grande

2005

Journal of the American Ceramic Society

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“…Instead, the planar defects investigated in this work have remained stable over more than 10 years and consist of Fe 2 O 2+α layers, as explained below. Similar intergrowths were previously observed in La-doped SrFeO 3-δ [26]. The global chemical composition of the SFO film was also measured by EDX revealing a slight Sr deficiency, such that Sr:Fe ≈ 0.96:1.00 (see Fig.…”

Section: A Structural Characterizationsupporting

confidence: 81%

Atomic structure and electronic properties of planar defects in SrFeO3−δ thin films

Rossell

Agrawal

Campanini

et al. 2020

Phys. Rev. Materials

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Extended planar defects found in epitaxially grown SrFeO 3-δ thin films are expected to exhibit distinct conductivity properties. Here, we use a combination of scanning transmission electron microscopy techniques and electron energy-loss spectroscopy (EELS) to uncover the peculiar structure of these planar defects and to explore their electronic properties. We find that the defects are formed by Fe 2 O 2+α layers consisting of FeO 5 polyhedra alternating with SrO and FeO 2 perovskite-type layers, analogous to the Sr 4 Fe 6 O 12+δ crystal structure. Our experimental and theoretical EELS data, combined with projected density of states calculations, reveal peak width changes and energies shifts, which suggest an increased electron doping of the Fe 3de g band in the Fe 2 O 2+α layers as compared to the SrFeO 3−δ film. Thus we show that the presence of Fe 2 O 2+α planar defects indeed can effectively modify the electron-hole conductivity in SrFeO 3-δ films.

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“…This perosvkite-related material has earned a lot of attention as possible candidate for oxygen separation membranes (e.g. [8]). It's precise crystal structure description lead to the detection of structural incommensurability [9].…”

Section: Introductionmentioning

confidence: 99%