About the crystal structure of La_1−xSr_xCoO_3−δ (0≤x≤0.6)

Abstract

The crystal structure of La1−xSrxCoO3−δ (0≤x≤0.6) has been studied, using powder X-Ray diffraction. The crystal structure shows a transition from rhombohedral distorted perovskite for LaCoO3−δ into cubic perovskite for La0.4Sr0.6CoO3−δ. The cubic unit cell parameter is ac=3.8342(1) Å for La0.4Sr0.6CoO3−δ, the space group probably being Pm3m. Using a hexagonal setting, the cell parameters for La0.5Sr0.5CoO3−δ, are a=5.4300(3) Å, c=13.2516(10) Å; a=5.4375(1) Å, c=13.2313(4) Å for La0.6Sr0.4CoO3−δ; a=5.4437(1) Å, c=13.2085(5) Å for La0.7Sr0.3CoO3−δ; a=5.4497(2) Å, c=13.1781(6) Å for La0.8Sr0.2CoO3−δ and a=5.4445(2) Å, c=13.0936(6) Å for LaCoO3−δ with the space group probably being R3c.

Synthesis, sintering, and thermoelectric properties of the solid solution La1–xSr x CoO3±δ (0 ≤ x ≤ 1)

“…6(a). These ceramics have high relative density (≈ 94%) [45]. However, for La 1−x Sr x CoO 3 samples densified at temperatures below 1473 K (x ≥ 0.8), Fig.…”

“…For 0 ≤ x ≤ 0.5, the diffraction patterns are indexed in a rhombohedral system (LaCoO 3 PDF Card No. 48-0123 [45]) with 3 R c space group ( Fig. 3(a)).…”

“…Apparent density of the samples was calculated from the weight and dimensions of the bars cut from the pellets for ZEM-3 characterization and the theoretical value [45].…”

Synthesis and structural characterization of Co-doped lanthanum strontium titanates

“…0.1) with Co content is displayed in Fig. 4 concentration between 0.0 and 0.3 show a relatively stable value, then it linearly decreases towards La 0.4 Sr 0.6 CoO 3 value [28] for y > 0.3. This variation corresponds to the position shift of the (024) reflection followed in Fig.…”

“…Lattice parameter as a function of cobalt content (y) in La 0.4 Sr 0.6 Ti 1Ly Co y O 3Dd calculated from Rietveld refinements ( y [ 1.0 value obtained from ICDD database PDF[28]). Error bars are the size of the symbols.…”