Preparation and properties of transition metal β″ aluminas
Abstract Ion exchange techniques were used to produce a family of 3d transition metal β″-aluminas by substitution of the sodium ion content in Na + -β″-alumina single crystals. Complete or nearly complete replacement was obtained for Cr 3+ , Mn 2+ , Co 2+ , and Ni 2+ compositions. Optical properties of the crystals were studied and both broad absorption and broad fluorescence bands were observed. Environmental exposure produced detrimental effects over long time periods, suggesting hydration of the conduction planes.