Influence of Sulfate Ion on Phase and Dispersion of Y_3Al_5O_(12) Nanopowders with the Co-Crystallization Method

摘要

Yttrium aluminum garnet Y_3Al_5O_(12) (YAG) nanopowders were synthesized from co-crystallized precursors of Y_2(SO_4)_3, Al(NO_3)_3-Al_2(SO_4)_3 and Y(NO_3)_3 with a three-layer core-shell structure. X-ray diffraction (XRD) pattern indicated that too much SO_4~(2-) was detrimental to the synthesis of pure phase YAG because of the serious separation between Y_2(SO_4)_3 and Al(NO_3)_3-Al_2(SO_4)_3. Transmission electron microscopy (TEM) revealed that SO_4~(2-) was beneficial for the dispersion of the powders owing to the high decomposition temperature of SO_4~(2-). The powders with the n(SO_4~(2-))/n(Y~(3+)) mole ratio of 1.5/3 calcined at 1050°C showed good sintering activity.