Phase relations in the LaNiO system: Influence of temperature and stoichiometry on the structure of La2NiO4

Odier, P.; Nigara, Yutaka; Coutures, Jean-Pierre; Sayer, M.

doi:10.1016/0022-4596(85)90249-x

Cited by 72 publications

(35 citation statements)

References 23 publications

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“…The La-Ni-O liquidus surface is unknown. The reported isothermal sections are mutually consistent assuming that the La 6 Ni 5 O 15 phase found by Kitayama [17] [14]. The authors observed rhombohedral LaNiO 3 , orthorhombic La 3 Ni 2 O 7 , tetragonal La 2 NiO 4 , NiO, and a mixture of unresolved phases of the series La n+1 Ni n O 3n+1 .…”

Section: Phase Diagramsupporting

confidence: 61%

“…The existence of La 2 NiO 4 (n = 1), La 3 Ni 2 O 7 (n = 2), La 4 Ni 3 O 10 (n = 3), and LaNiO 3 (n = ∞) has been confirmed in many reports [11][12][13][14][15]. Attempts to obtain single-phase compounds with n ≥ 4 were not successful although they may form on the nanometer scale as intergrowths in the structure of La 3 Ni 2 O 7 and La 4 Ni 3 O 10 [16].…”

Section: Solid Phasesmentioning

confidence: 79%

“…Phase diagrams of the La-Ni-O system are available as partial isothermal sections at 1373 and 1473 K [17,36,49], a pseudobinary section La 2 O 3 -NiO [50][51][52], and a vertical section along the La 2 NiO 4 -LaNiO 3 join [14,49]. The La-Ni-O liquidus surface is unknown.…”

Section: Phase Diagrammentioning

confidence: 99%

See 2 more Smart Citations

Thermodynamic analysis of the ternary La–Ni–O system

Zinkevich

Aldinger

2004

Journal of Alloys and Compounds

117

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Section: Phase Diagramsupporting

confidence: 61%

Section: Solid Phasesmentioning

confidence: 79%

See 1 more Smart Citation

Thermodynamic analysis of the ternary La–Ni–O system

Zinkevich

Aldinger

2004

Journal of Alloys and Compounds

117

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“…It is clear from the obtained R values that when 25% of iron is introduced in the B site of LaNiO , temperatures of synthesis as high as 1000°C can be used without observing decomposition. This is in contrast to LaNiO , which decomposes at temperatures higher than 860°C (23)(24)(25)(26)(27). A slight decomposition, evidenced by the high R value and by some impurity lines (shown in the inset of Fig.…”

Section: Since Lafementioning

confidence: 63%

Crystal Structure Refinement and Stability of LaFexNi1−xO3Solid Solutions

Falcón

Goeta

Punte

et al. 1997

Journal of Solid State Chemistry

123

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“…Odier et al 31 34 which show that minor deviations from the nominal La:Ni ratio should have a strong effect on the stability limit. This stability limit may vary from an upper oxygen partial pressure value for a slight excess of nickel (Ni + ½O 2 ↔ NiO) to a lower limit for a slight excess of lanthanum oxide In IS-3, the capillary is sealed and it would therefore be expected that the oxygen pressure in the capillary would increase on heating, however from Rietveld refinement of the XRD data under these conditions it is apparent that LNO is reduced to form La 2 O 3 and Ni.…”

Section: Is-3: Sealed Capillarymentioning

confidence: 99%

In situ compatibility studies of lanthanum nickelate with a ceria-based electrolyte for SOFC composite cathodes

et al. 2012

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The phase stability and compatibility of intermediate temperature solid oxide fuel cell (IT-SOFC) composite cathodes of lanthanum nickelate, La 2 NiO 4+δ (LNO), and ceria-gadolinium oxide, Ce 0.9 Gd 0.1 O 2-δ (CGO10), have been investigated by high resolution synchrotron X-ray diffraction (XRD). No reaction was observed between LNO and CGO10 at temperatures of up to 900°C when the composite is open to an ambient air environment. However, in a sealed capillary environment the 50:50 wt% LNO:CGO10 composite undergoes a partially reversible reaction at temperatures of 750°C and above, whereby LNO decomposes to La 2 O 3 and Ni. Changes in the CGO10 Bragg peaks indicate that this component is actively involved in this process. This study shows that the phase stability of LNO:CGO10 composites is highly dependent on oxygen partial pressure. In addition, it is observed that ex-situ XRD is insufficient to determine the presence of reactivity in composite cathodes and that high resolution in-situ XRD measurements are required to obtain details of the complexity of phase stability in SOFC composite cathodes. Figure 1 oriented with the b axis in the long direction; a slight tilting of the nickel octahedra can be seen in the Bmab structure shown in Figure 1(a). From the studies discussed above 7, 18-21 it appears that LNO reacts with fluorite structured ceria based electrolytes and is apparently stable in contact with perovskite-type lanthanum gallate. However, all of these studies were performed using ex-situ XRD, that is, XRD was performed at room temperature after the composite had been annealed. With this method it is not possible to monitor any reactions as they develop, as either a function of temperature or time, nor is it possible to identify whether there is any degree of reversibility. This study differs from those previously undertaken through the use of in-situ synchrotron XRD, enabling a detailed probing of the reaction mechanisms as a function of temperature, time and environment. Whilst it is apparent from the ex-situ XRD studies, that there is ready formation of higher order Ruddlesden-Popper phases under certain conditions, it is likely that LNO phase stability is sensitive to oxygen partial pressure and temperature and there is a need to 5 investigate the reaction as it develops; for this reason, we have undertaken in-situ studies of LNO:CGO10 composites using high resolution synchrotron X-ray powder diffraction. ExperimentalA 50:50 wt% composite of LNO:CGO10 was created from LNO powder (Cerpotech) and CGO10 powder (Praxair), which were calcined separately at 1400°C for 5 hours. The relative weight percentage of each powder was measured for the desired composition and the mixture was ballmilled with zirconia mixing balls for 24 hours in ethanol. The resultant composite powder was dried at 100°C for 16 hours. All synchrotron X-ray diffraction patterns were obtained on beamline I11 at the Diamond Light Source, UK. Technical descriptions of the I11 instrument can be found in the paper by Thompson et...

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Phase relations in the LaNiO system: Influence of temperature and stoichiometry on the structure of La2NiO4

Cited by 72 publications

References 23 publications

Thermodynamic analysis of the ternary La–Ni–O system

Thermodynamic analysis of the ternary La–Ni–O system

Crystal Structure Refinement and Stability of LaFexNi1−xO3Solid Solutions

In situ compatibility studies of lanthanum nickelate with a ceria-based electrolyte for SOFC composite cathodes

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