High-temperature neutron scattering investigation of pure and doped lanthanum gallate

Lerch, Martin; Boysen, H.; Hansen, Thomas C.

doi:10.1016/s0022-3697(00)00078-0

Cited by 108 publications

(113 citation statements)

References 15 publications

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“…The curve feature in the diffusion pathway of oxide ions in cubic perovskite-type ABO3-δ ionic and mixed conductors might be common regardless of atomic species A and B. This conclusion is consistent with the theoretical calculations 23) and probability density function analysis 24) in the literature. Neutron powder diffraction patterns of La0.64(Ti0.92Nb0.08)O2.99 at 496°C, 1008°C and 1358°C indicated a double perovskite-type structure with tetragonal P4/mmm space group (a ≈ ap × b ≈ ap × c ≈ 2ap; the subscript p denotes a pseudo cubic perovskitetype structure) (Fig.…”

Section: Jcs-japansupporting

confidence: 90%

Diffusion pathway of mobile ions and crystal structure of ionic and mixed conductors - A brief review

Yashima

2009

J. Ceram. Soc. Japan

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A brief review on the field of Solid State Ionics, including the diffusion pathway of mobile ions, crystal structure and materials, is presented. In the fluorite-structured ionic conductors such as ceria solid solution Ce0.93Y0.07O1.96, bismuth oxide solid solution δ -Bi1.4Yb0.6O3 and copper iodide CuI, a similar curved diffusion pathway along the <100> directions is observed. In the ionic and mixed conductors with the cubic ABO3 perovskite-type structure such as lanthanum gallate and lanthanum cobaltite solid solutions, the mobile ions diffuse along a curved line keeping the interatomic distance between the B cation and O 2-anion to some degree.

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Section: Jcs-japansupporting

confidence: 90%

Diffusion pathway of mobile ions and crystal structure of ionic and mixed conductors - A brief review

Yashima

2009

J. Ceram. Soc. Japan

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“…23 Indeed, a neutron scattering study of pure and doped LaGaO 3 by Lerch et al 17 provides evidence for our predicted curved path using a detailed analysis of the Debye-Waller factors including anharmonic contributions. More recently, our pathway has also been confirmed by neutron diffraction studies 18 of doped LaGaO 3 using the nuclear density distribution.…”

Section: Mechanism and Energetics Of Oxygen Ion Migration In Lamo 3 Pmentioning

confidence: 60%

“…An electrochemical reactor with a ceramic proton-conducting membrane based on doped BaZrO 3 has also been used to study the electrochemical promotion of catalysis. 6 Also in this field of conducting solids, the oxygen transport properties of the LaGaO 3 -based perovskite have been widely investigated, [8][9][10][11][12][13][14][15][16][17][18] owing to the higher oxygen ion conductivity than the conventional Y/ZrO 2 electrolyte at lower temperatures. The incorporation of cation dopants to form the system La 1Ϫx -Sr x Ga 1Ϫy Mg y O 3Ϫδ (often termed LSGM) gives rise to the highly mobile oxygen vacancies that are responsible for the observed † Based on the presentation given at Dalton Discussion No.…”

Section: Introductionmentioning

confidence: 99%

Doping and defect association in AZrO3(A = Ca, Ba) and LaMO3(M = Sc, Ga) perovskite-type ionic conductors

et al. 2004

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Computer simulation techniques have been used to investigate the defect chemistry of perovskite-structured ionic conductors based upon AZrO 3 (A = Ca, Ba) and LaMO 3 (M = Sc, Ga). Our studies have examined dopant site-selectivity, oxide ion migration and dopant-defect association at the atomic level. The energetics of dopant incorporation in AZrO 3 show strong correlation with ion size. We predict Y 3ϩ to be one of the most favourable dopants for BaZrO 3 on energetic grounds, which accords with experimental work where this cation is the commonly used acceptor dopant for effective proton conduction. Binding energies for hydroxy-dopant pairs in BaZrO 3 are predicted to be favourable with the magnitude of the association increasing along the series Y < Yb < In < Sc. This suggests that proton mobility would be very sensitive to the type of acceptor dopant ion particularly at higher dopant levels. Oxygen vacancy migration in LaScO 3 is via a curved pathway around the edge of the ScO 6 octahedron. Dopant-vacancy clusters comprised of divalent dopants (Sr, Ca) at the La site have significant binding energies in LaScO 3 , but very low energies in LaGaO 3 . This points to greater trapping of the oxygen vacancies in doped LaScO 3 , perhaps leading to higher activation energies at increasing dopant levels in accord with the available conductivity data.

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“…62) at room temperature, and rhombohedral above 172ºC by X-ray diffraction, scanning and transmission electron microscopy. Whereas, Lerch et al [6] carried out powder neutron diffraction measurements and concluded that the crystal structure of LSGM was orthorhombic with space group Imma (No. 74) at room temperature and cubic with space group (No.…”

Section: Introductionmentioning

confidence: 99%

Effect of Sintering Temperatures on the Crystal Structures of La0.9Sr0.1Ga0.8Mg0.2O3−δ

Zhang¹,

Gao²,

Lu³

et al. 2017

dtmse

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Abstract. The crystal structures of electrolyte materials of La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) for solid oxide fuel cells prepared by low-and high-temperature solid state reactions and laser rapid sintering are studied by structural refinements of XRD patterns. The results of structural refinements show that the three series of samples by low-and high-temperature solid state reactions and laser rapid sintering crystallized in different structures. They are identified to be cubic with space group m m P  3 (denoted as C-LSGM), monoclinic with space group I2/a (denoted as M-LSGM) and orthorhombic with space group Imma (denoted as O-LSGM), respectively. To understand the effect of sintering temperatures on the crystal structures, the Gibbs free energies of three structures are calculated. It indicates that the cubic phase has the priority to form at relatively lower temperatures due to its lowest Gibbs energy while the formation of monoclinic and orthorhombic phases requires higher and highest sintering temperatures. This is in agreement with the experiment conditions of the preparation of the three series of samples.

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High-temperature neutron scattering investigation of pure and doped lanthanum gallate

Cited by 108 publications

References 15 publications

Diffusion pathway of mobile ions and crystal structure of ionic and mixed conductors - A brief review

Diffusion pathway of mobile ions and crystal structure of ionic and mixed conductors - A brief review

Doping and defect association in AZrO3(A = Ca, Ba) and LaMO3(M = Sc, Ga) perovskite-type ionic conductors

Effect of Sintering Temperatures on the Crystal Structures of La0.9Sr0.1Ga0.8Mg0.2O3−δ

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