Solid-State Synthesis of Dy<SUB>3</SUB>Al<SUB>5</SUB>O<SUB>12</SUB> Using Dy<SUB>2</SUB>O<SUB>3</SUB> and Al<SUB>2</SUB>O<SUB>3</SUB> Powders

Abstract

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 diffraction using Si powder as a standard. The Dy-Al oxide system has three compounds consisting of garnet, perovskite and monoclinic. In the case of using any starting powders of the three compound compositions, the perovskite phase was most easy to form. The garnet single phase was difficult to form at the heating process up to 1700°C even using garnet composition powders. The difficulty to form the garnet phase was also studied in a phase formation of the R3Al5O12-R3Ga5O12 (R: Dy, Y and Gd) solid solution using garnet-composition powders on the basis of ionic radii of rare-earth elements.