Chemically induced order disorder transition in magnesium aluminium spinel

Magnesium aluminate spinel (MgAl2O4) spinel powder was synthesized by nitrate citrate auto-ignition route taking different ratios of nitrate and citrate solution. The ‘as prepared’ black ash was calcined at different temperatures in the range 650–1250 °C for 9 h. Phase evolution of calcined powder samples as studied by X-ray diffraction indicates the presence of disorder at lower calcination temperatures, which transforms to an ordered structure at higher calcination temperatures. Finally, Raman spectroscopy confirms the order–disorder phase transition in spinel sample.