Thermodynamic Properties of LaCrO₄, La₂CrO₆, and La₂Cr₃O₁₂, and Subsolidus Phase Relations in the System Lanthanum–Chromium–Oxygen

Abstract

In the system La-Cr-O, there are three ternary oxides (LaCrO 4

High‐Temperature Electrical Conductivity of LaCr1−xCoxO3 Ceramics

“…Traces of secondary phases such as LaCrO 4 and La 2 CrO 6 were detected in the synthesized powders. Monoclinic LaCrO 4 and orthorhombic La 2 CrO 6 are intermediate phases which can be formed during synthesis, and decompose when annealed in ambient air atmosphere (LaCrO 4 →LaCrO 3 + ½ O 2 at 734°C and La 2 CrO 6 →LaCrO 3 + ½ La 2 O 3 + 3/4 O 2 at 864°C) . Hence, all compositions revealed the presence of single‐phase perovskite only after sintering.…”

“…(1) Microstructure The major crystalline phase determined by XRD (not shown) in the synthesized powder was LaCr 1Àx Co x O 3 with orthorhombic symmetry for x = 0.0, 0.1, and 0.2 and rhombohedral symmetry for x = 0.3, respectively. Traces of secondary phases such as LaCrO 4 24 Hence, all compositions revealed the presence of single-phase perovskite only after sintering. LaCr 1Àx Co x O 3 showed mainly orthorhombic symmetry for 0.0 ≤ x ≤ 0.2 and rhombohedral symmetry for x = 0.3.…”

The preparation of large surface area lanthanum based perovskite supports for AuPt nanoparticles: tuning the glycerol oxidation reaction pathway by switching the perovskite B site

“…An example of an extremely complicated system is the La–Cr–O system, where a number of ternary oxide phases are possible (LaCrO 4 , La 2 Cr 3 O 12 , La 2 CrO 6 and LaCrO 3 ) depending on the phase composition and temperature. 27 These phases decompose at specific temperatures to produce LaCrO 3 and O 2 . Potentially, the mass losses centred at 520 °C and 785 °C represent phase decomposition of La 2 Cr 3 O 12 and La 2 CrO 6 , respectively.…”

Rapid Laser Processing of Thin Sr‐Doped LaCrO3–δ Interconnects for Solid Oxide Fuel Cells

“…[ 39 ] Very weak XRD peaks (suggested with * in Figure 1b) are attributed to La 4.67 [SiO 4 ] 3 O, [ 40 ] which indicates a small amount of agate was contaminated during the ball‐milling stage. These XRD patterns suggest that RLRS can prepare Sr‐doped LaCrO 3– δ in a few minutes without residual intermediate phases (e.g., SrCrO 4 , [ 10 ] LaCrO 4 [ 41–43 ] ).…”

“…LaCrO 4 was also identified in this sample, indicating that thermal energy given by the laser irradiation at this condition is insufficient for the decomposition of LaCrO 4 to LaCrO 3 . [ 42 ] Likewise, the stronger and faster laser condition was unsuitable for the RLRS of La 0.8 Sr 0.2 CrO 3– δ because the sample color changed only nearby the ending part of laser scanning (scanning was conducted from right to left). This is most likely because that the laser heating was not sufficient at beginning due to heat dissipation and became sufficient near completion of the scan by heat accumulation.…”