Thermodynamic and Cation Diffusion Studies of Perovskites on the Basis of LaGaO3 and Implications for SOFC

Effect of sintering time on structural, microstructural and chemical composition of Ni-doped lanthanum gallate perovskites

“…However, that solid solubility limit is still controversial in the literature. Matraszek et al [13] found lower values than those determined by Majewski et al [12] at the same temperature. Matraszek et al [13] Unfortunately, as was mentioned above the La 2 O 3 -SrO-Ga 2 O 3 -NiO quaternary phase diagram has not been outlined yet.…”

“…In summary, the samples sintered for 6 h are constituted by a perovskite with an experimental composition very close to the nominal one and a second phase, being La 1.18 Sr 1.00 Ga 3.04 O 7.33 for x ¼0.00, La 1.20 Sr 1.00 (Ga 1.00 ,Ni 0.01 ) 3.00 O 7.33 for x¼ 0.10, and (La 0.78 , Sr 0.22 ) 4.50 (Ga 0.53 ,Ni 0.65 ) 2.00 O 9.15 for x ¼0.20, respectively. LaSrGa 3 O 7and La 4 Ga 2 O 9 second phases were also found by other authors[12][13][14][15] in samples sintered between 1300 and 1400 1C in which the main phase is the (La,Sr)(Ga,Mg)O 3.00 À δ perovskite. In our study those second phases admit Ni 2 þ in their lattices, as is observed in their respective formulas.ForLa 0.90 Sr 0.10 GaO 2.95 sintered for 48 h two different grey tones (light and medium grey); labelled as 1 and 2, respectively, Fig.…”

“…Matraszek et al [13] found lower values than those determined by Majewski et al [12] at the same temperature. Matraszek et al [13] Unfortunately, as was mentioned above the La 2 O 3 -SrO-Ga 2 O 3 -NiO quaternary phase diagram has not been outlined yet. However, all of this information about binary, ternary and the related quaternary systems gives us an idea of the complexity of the quaternary system La 2 O 3 -SrO-Ga 2 O 3 -NiO.…”

SOFC test using Ba0.5Sr0.5Co0.8Fe0.2O3−δ as cathode on La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte

“…LSGM has an ionic conductivity of about 0.1 S cm − 1 at 1073 K, good chemical stability and negligible electronic conduction over a broad range of oxygen partial pressures (10 − 20 to 1 atm) [5]. However, it has some drawbacks as electrolyte such as undesired segregation of LaSrGa 3 O 7 and LaSrGaO 4 during its synthesis [6] and chemical incompatibility with Ni-based anode materials [7][8][9]. Nevertheless, the synthesis can be optimized to reduce undesired phases and alternative anode material can be used.…”

Preparation of high-density La0.90Sr0.10Ga1−yMgyO3−δ (y=0.20 and 0.30) oxide ionic conductors using HIP

“…The identification of the secondary phase was difficult. However, Matraszek et al[15] reported that the secondary phase in the case of high magnesium composition was MgGaLa3 O 7 . On the other hand, the HIPed pellet consisted of a single phase of LSGM perovskite.…”