Thermal expansion of Sr- and Mg-doped LaGaO3

Hayashi, Haruyuki; Suzuki, Masahide; Inaba, Hideaki

doi:10.1016/s0167-2738(99)00346-x

Cited by 88 publications

(49 citation statements)

References 23 publications

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“…Sr-and Mg-doped LaGaO 3 oxides have the highest electrical conductivity among them, with ionic transference number close to one over a wide range of oxygen pressures, and are used as interconnect and electrolyte materials in SOFC (Hayashi et al 1999). Data on the thermal expansion of doped LaGaO 3 has been reported by Feng and Goodenough (1994), Stevenson et al (1997), Ishihara et al (1998), Hayashi et al (1999, 2000 and Aleksandrovskii et al (2001). Stevenson et al (1997) measured linear thermal expansion (TEC) coefficient of two Sr-and Mg-doped LaGO 3 samples from 293 to 1473 K. The TEC was found to increase with increasing temperature.…”

Section: Introductionmentioning

confidence: 95%

“…Although their data show gradual increase in the slopes of thermal expansion with temperature, the authors conclude that the temperature dependence of expansion is insignificant and the phase transition found in LaGaO 3 around 420 K disappeared in the thermal expansion curve of dopedLaGaO 3 (Ishihara et al 1998). Hayashi et al (2000) measured TEC of La 0⋅9 Sr 0⋅1 Ga 1-y Mg y O 3-δ (y = 0⋅1 to 0⋅3) and La 0⋅8 Sr 0⋅2 Ga 1-y Mg y O 2⋅85 (y = 0⋅1, 0⋅2) in the temperature range from 100 to 873 K and showed that doping increases thermal expansion. Pure LaGaO 3 exhibited a shrinkage related to orthorhombic to rhombohedral structure transition at 421 K (Hayashi et al 2000).…”

Section: Introductionmentioning

confidence: 99%

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Thermal expansion of doped lanthanum gallates

et al. 2010

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Thermal expansion of several compositions of Sr and Mg-doped LaGaO 3 including an A-site deficient composition (La 0⋅9 Sr 0⋅1 ) 0⋅98 (Ga 0⋅8 Mg 0⋅2 )O 2⋅821 were measured in the temperature range from 298 to 1273 K. The effect of doping on thermal expansion was studied by varying the composition at one site of the perovskite structure (either A or B), while keeping the composition at the other site invariant. Thermal expansion varied nonlinearly with temperature and exhibited an inflexion between 550 and 620 K, probably related to the change in crystal structure from orthorhombic to rhombohedral. The dependence of average thermal expansion coefficient (α av ) on the dopant concentration on either A or B site of the perovskite structure was found to be linear, when the composition at the other site was kept constant. Mg doping on the B-site had a greater effect on the average thermal expansion coefficient than Sr doping on the A-site. Cation deficiency at the A-site decreases thermal expansion when compositions at both sites are held constant.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Thermal expansion of doped lanthanum gallates

et al. 2010

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“…Hayashi et al 24 and the authors reported the thermal expansion properties of LSGM. The thermal expansion is increased with increasing the dopant amount.…”

Section: Application Of Lsgm For the Electrolyte Of Sofcmentioning

confidence: 99%

Development of New Fast Oxide Ion Conductor and Application for Intermediate Temperature Solid Oxide Fuel Cells

Ishihara¹

2006

Bulletin of the Chemical Society of Japan

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Solid Oxide Fuel Cell (SOFC) show great promise as new power generators with high efficiency. Decreasing the operating temperature is critically required for the further development of SOFC. This review introduces that oxide ion conductivity in the perovskite oxide of LaGaO 3 , which was found by our group. LaGaO 3 doped with La and Mg exhibits the high oxide ion conductivity over a wide P O2 range; the value is higher than that of Y 2 O 3 -stabilized ZrO 2 by an order of magnitude. When LaGaO 3 -based oxide was used as the electrolyte of SOFC, the power density could be improved greatly, in particular over the low-temperature range. In this study, the power generating property of LSGM using a thin film of LaGaO 3 is also introduced. The maximum power density of the cell using LaGaO 3 -based oxide is as high as 0.6 W cm À2 at 773 K. This suggests that SOFC could be operable at temperature lower than 773 K.

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“…for practical proposes, these TEC values tend to increase sharply above a certain temperature. Such behaviour was associated to extensive oxygen losses, that cause lattice expansion [26] and hence higher TEC values, due to the change of the oxidation state of the transition metal cations. These changes are limited in CaTi 1−x Fe x O 3−δ , since the fraction of Fe 4+ , as determined by Mössbauer spectroscopy, was never higher than 20% of the total number of Fe cations [15].…”

Section: Thermal Expansionmentioning

confidence: 99%

Properties of CaTi1 ? xFexO3 ? ? Ceramic Membranes

et al. 2004

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CaCO 3 , TiO 2 and Fe 2 O 3 were mixed in the appropriate stoichiometric quantities and calcined at 1100 • C for 10 h. These powder mixtures were uniaxially pressed and sintered at temperatures ranging from 1350 to 1500 • C for 2 h in order to obtain dense disk-shaped samples with nominal CaTi 1−x Fe x O 3−δ (x = 0.05, 0.15, 0.20, 0.40 and 0.60) compositions. Dilatometry and in situ high temperature powder X-ray diffraction analysis showed a good agreement on the thermal expansion behaviour of these materials between room temperature and 1000 • C. The estimated linear thermal expansion coefficient is close to 13 × 10 −6 K −1 and is little affected by composition. No evidence for surface carbonation was detected in the infrared spectra collected on samples previously annealed in CO 2 atmospheres. The oxygen permeability measured at temperatures ranging from 750 to 1000 • C goes through a sharp maximum for x = 0.20. This result is interpreted by structural differences related to change from disordered to ordered oxygen vacancies. The overall performance of CaTi 0.80 Fe 0.20 O 3−δ is compared to other mixed conducting materials.

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Thermal expansion of Sr- and Mg-doped LaGaO3

Cited by 88 publications

References 23 publications

Thermal expansion of doped lanthanum gallates

Thermal expansion of doped lanthanum gallates

Development of New Fast Oxide Ion Conductor and Application for Intermediate Temperature Solid Oxide Fuel Cells

Properties of CaTi1 ? xFexO3 ? ? Ceramic Membranes

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