SOLID-STATE SYNTHESIS OF DY3AL5O12 USING DY2O3 AND AL2O3 POWDERS

Phase-formation process in solid-state synthesis of DY3Al5O12 has been investigated at the heating and isothermal processes using Dy2O3 and Al2O3 powders. Phase formation was determined by powder X-ray diffract ion using Si powder as a standard. The DY-Al oxide system has three co mpounds consisting of garnet, perovskite and monoclinic. In the case o f using any starting powders of the three compound compositions, the p erovskite phase was most easy to form. The garnet single phase was dif ficult to form at the heating process up to 1700 degrees C even using garnet composition powders. The difficulty to form the garnet phase wa s also studied in a phase formation of the R(3)Al(5)O(12)-R(3)Ga(5)O(1 2)(R: DY, Y and Gd) solid solution using garnet-composition powders on the basis of ionic radii of rare-earth elements.