Sucrose combustion synthesis of LaxSr(1−x)MnO3 (x ≤ 0.2) powders

An energy efficient combustion synthesis has been used for the preparation of nanocrystalline LSM powder of composition La1−xSrxMnO3 (x < 0.2) using sucrose as a polymerisable fuel. Nitrate salt of La3+ and Sr2+ and acetate of Mn2+ were dissolved in water along with sucrose and concentrated by heating in to the form of a viscous resin which is then transformed in to macro porous foam by drying at 120 °C. Phase pure LSM has been obtained by combustion of these foams initiated with a matchstick in a set up fabricated in our laboratory. A minimum of 2 moles of sucrose is required for one mole of LSM ions for the formation of perovskite LSM phase. The LSM powder obtained by planetary milling of the combustion ash shows particle size in the range 0.1-6 μm with a D50 value ∼0. 2 μm. The crystallite size calculated from XRD data using Scherer equation is in the range 13.12-17.9 nm. More than 97% TD has been achieved by cold compaction and sintering at of these powders.