Low-temperature synthesis of micro/nano Lithium Fluoride added magnesium aluminate spinel

Abstract In this study, a significant decrease in temperature for the phase formation of magnesium aluminate spinel in presence of nano-Lithium Fluoride additive during the solid-state process has been evaluated. Adding 1 wt% of micron LiF to the Stoichiometric content of alpha alumina and magnesia nanopowders resulted in the decrease of temperature for spinel phase formation from 1650 °C to 1450 °C. Furthermore, decreased size of LiF additive from micron to nano lowered the spinel phase formation temperature from 1450 °C to 1200 °C. Average particle diameter (D50) of spinel powder has been decreased from 475 nm to 275 nm in a normal procedure (using micron LiF) and by using nano LiF additive this particle size has been decreased further up to 110 nm. The synthesized spinel powder at 1200 °C kept for 2 h was calculated 99.8% pure, and the particles were finer and homogeneously distributed with an average size of 110 nm, and a specific surface area of 17 m2/g.