Physiochemical properties of combustion synthesized La_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ perovskite: A role of fuel to oxidant ratio

Abstract The solution combustion synthesis is a novel approach to synthesize the nanocrystalline materials with an unexpectedly high surface to volume ratio. Thus, in present paper, La_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ powders have been synthesized by solution combustion synthesis route at different fuel to oxidant ratio (ψ) and its effect on different physiochemical properties have been studied. The mode of propagation of combustion reaction changed from smoldering to volume with increasing ψ. The thermal analysis shows that exothermicity increased with ψ resulting into enhanced agglomeration as confirmed from particle size distribution. Typically, the size of agglomerate varies from 0.59 to 1.56 μm. The XRD and FT-IR patterns reveal that the phase pure La_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ is formed at the ψ=2. The TEM particles size is 25 nm. La_0.6Sr_0.4Co_0.8Fe_0.2O_3-δ powder shows the higher catalytic activity at about 426 °C.