Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates

Abstract

This paper reports on the results concerning the sol-gel preparation and characterization of Sr-substituted perovskite lanthanum cobaltates La 1-x Sr x CoO 3-d (x = 0.0, 0.25, 0.5 and 0.75). The metal ions, generated by dissolving starting materials in diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the non-substituted and Sr-substituted LaCoO 3 . The influence of the synthesis temperature, heating time and the amount of substituent on the phase purity of La 1-x Sr x CoO 3-d were investigated. The phase transformations, composition and micro-structural features in the gels and polycrystalline samples were studied by thermal analysis (TG/DTA), infrared spectroscopy (IR), powder X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). © Versita Warsaw and Springer-Verlag Berlin Heidelberg.

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

“…All the diffraction peaks of samples calcined at 500-700°C are well matched with La 0.7 Sr 0.3 FeO 3 (JCPDS 89-1269), respectively, except a small peak located at 25.2°( 2h) corresponding to SrCO 3 phase (JCPDS 05-0418). This phenomenon was also observed by Karpinski et al [22,23]. Most of the alkaline earth metal oxides and rare earth metal oxides, in particular BaO, SrO, and Re 2 O 3 , contain metal carbonate [24,25].…”

Microstructure of Nanoscaled La0.6Sr0.4CoO3‐δ Cathodes for Intermediate‐Temperature Solid Oxide Fuel Cells

“…These findings agree with literature data obtained by X‐ray diffraction. Cizauskaite and Kareiva investigated LSC samples with different Sr‐concentrations also fabricated by a sol‐gel process 37. They demonstrated that a single‐phase perovskite is formed at calcination temperatures between 900 and 1000 °C.…”

“…Cizauskaite and Kareiva investigated LSC samples with different Sr-concentrations also fabricated by a sol-gel process. [ 37 ] They demonstrated that a single-phase perovskite is formed at calcination temperatures between 900 and 1000 ° C. At lower temperatures they found the formation of metastable phases like Co 2 O 3 , SrCO 3 [ 38 ] La 2 CoO 4 is also known to be formed if the perovskite-type LaCoO 3 is reduced at high temperatures. [ 39 ] wileyonlinelibrary.com The grayscale histogram of the image stack of sample LSC800 is displayed in Figure 4 c. It shows the voxel frequency in dependence of the grayscale value.…”

“…Cizauskaite and Kareiva investigated LSC samples with different Sr-concentrations also fabricated by a sol-gel process. [ 37 ] They demonstrated that a single-phase perovskite is formed at calcination temperatures between 900 and 1000 ° C. At lower temperatures they found the formation of metastable phases like Co 2 O 3 , SrCO 3 and SrO. Depending on the used solgel chemistry Co 3 O 4 was found up to 1000 ° C annealing temperature.…”

Synthesis and Evaluation Catalytic Efficiency of Perovskite-Type Oxide Nanopowders in Removal of Bromocresol Purple from Aqueous Solution

“…A number of approaches such as solid-state reactions (Zhou et al, 2006), mechanical-synthesis (Szabo et al, 2002), coprecipitation (Nakayama et al, 2003;Srdic et al, 2005), solution combustion or thermal decomposition (Bansal and Zhong, 2006;Berger et al, 2004;Berger et al, 2007) hydrothermal, and sol-gel technique (Pechini, 1967;Cizauskaite and Kareiva, 2008) have been used to synthesize LaMO 3 -based perovskite powders. The solgel method is highly attractive because various metal ions are chelated to form metal complexes in solution and are uniformly distributed at the molecular level.…”