Sol-gel synthesis and properties of doped lanthanum chromite nanopowders

Abstract

La 1 -x Sr x CrO 3 (0.2 ≤ x ≤ 0.3) powders have been prepared by a sol-gel process and dried in a microwave oven. Synthesis conditions were optimized using differential scanning calorimetry and mass spec trometry data. The phase composition of the synthesis products obtained at temperatures of 800, 850, 900, and 950°C was determined by X ray diffraction. Scanning electron microscopy was used to determine the particle size of the powders and examine their morphology.

Preparation and Structural Characterization of Complex Oxide Eutectic Precursors from Polymer–Salt Xerogels Obtained by Microwave-Assisted Drying

“…Synthesis in polymer-salt systems. This technique supports the same concept as the Pechini method, and the gel-forming media here are water-soluble polymers, primarily polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP) and methylcellulose [11][12][13][14][15]. Sol-gel synthesis based on polymer-salt solutions has been successfully implemented to obtain nanoscale powders and thin films of various inorganic compounds, especially those with complex metal anions (i.e., tungstates, molybdates and manganates [11,12]).…”

“…Separate inorganic and organic samples were prepared by drying respective aqueous solutions in a laboratory microwave system (Discover BenchMate, CEM Corp., Matthews, NC USA) @ 2455 MHz to constant mass. Oxide eutectic compositions were prepared from polymer-salt solutions as discussed in [13,15]. Proper amounts of inorganic salts, calculated from ignition loss, were dissolved in 10% wt.…”

“…Sol-gel synthesis based on polymer-salt solutions has been successfully implemented to obtain nanoscale powders and thin films of various inorganic compounds, especially those with complex metal anions (i.e., tungstates, molybdates and manganates [11,12]). Synthesis of complex oxide compounds (i.e., cordierite [13], aluminomagnesian spinel [14] and lanthanum chromite [15]) has also been reported.…”

“…Here, we report the PSSG synthesis and the physico-chemical properties of batch compositions in two ternary systems, CaO-Al 2 O 3 -Y 2 O 3 and MgO-Al 2 O 3 -Y 2 O 3 , obtained with microwave-assisted drying, as suggested in [13][14][15], for further use as sintering aids in silicon carbide ceramics. Here, the effect of different ionic composition was studied, and different water-soluble polymers were employed, namely fully saponated PVA, high-weight PVP and Na-salt of carboxymethylcellulose (Na-CMC).…”