pH effects on formation of cerium-doped terbium aluminum garnet (Tb2.95Al5O12:Ce0.05) phosphor powder

Terbium aluminum garnet (TAG) was successfully synthesized by a solid-state reaction method in this study. Before calcining, the mixing powder of terbium oxide (Tb4O7), boehmite (AlOOH), and cerium chloride (CeCl3 center dot 7H(2)O) was aged at pH 1, 2, and 3, respectively. Experimental results revealed that the better process for the formation of TAG powder was aged at pH 1. The effects of pH on the formation of TAG powder were further studied. The diffusion distance between terbium oxide and boehmite was reduced by aging the mixed slurry at pH 1. A pure phase of TAG powder was obtained after the aged mixture of boehmite, terbium oxide, and cerium chloride was heated at 1200 degrees C for 2 h and then calcined at 1500 degrees C for 20 h. The particle size of pure TAG powders is the agglomerate morphology through scanning electron microscopy observation. The formed TAG powder in this work had a maximum emission peak in 553 nm as exciting at 470 nm. (c) 2006 The Electrochemical Society.