Precipitation and Calcination Processes for Yttrium Aluminum Garnet Precursors Synthesized by the Urea Method

Abstract

Yttrium aluminum garnet (YAG) precursors for transparent ceramics were synthesized by the urea method under various [urea]/[metal ions] ([U]/[M]) conditions. Monophase YAG was obtained from solutions with a high [U]/[M] ratio after calcination at a temperature of 1200°C. The condition of the precipitates seemed to indicate that the yttrium compounds had precipitated onto the aluminum compounds. The surface morphology and size of the particles were controlled by the [U]/[M] ratio. The different reaction sequences of YAG crystallization for low‐ and high‐ratio samples were dependent on morphology, size, and the quantity of chemical species that was precipitated as carbonate and/or sulfate compounds.