Synthesis and processing of spinel powders for transparent ceramics

Spinel powders have been synthesized by chemical coprecipitation using two different precursors, nitrates and chlorides, and by an oxides mixture route. It has been shown that depending on the precursors used and the synthesis conditions pure spinel nanopowder can be obtained at different temperatures and with different levels of agglomeration. According to TEM results, the chloride route allows obtaining pure and deagglomerated spinel powders after calcination at 800 °C with a submicrometer particle size. Sintered lyophilized powders obtained by a chloride route allow achieving materials with in-line transmittances close to 46% at 540 nm and 83% in the infrared range.