Effect of the Melt Temperature on the Solidification Process of Liquid Garnets Ln ₃ Al ₅ O ₁₂ (Ln = Dy, Y, and Lu)

Abstract

The solidification process of liquid garnets Ln 3 Al 5 O 12 (Ln = Dy, Y, Lu) was probed by differential thermal analysis. A critical temperature T clg was evidenced in the liquid. Cooling from temperatures under T clg leads to the crystallization of the single garnet phase. Cooling from temperatures above T clg leads to the solidification of a mixture of perovskite LnAlO 3 and aluminum oxide α‐Al 2 O 3 . For Ln = Y, the results are in agreement with stable and metastable phase diagrams previously proposed. The YAIO 3 melt was shown to display a critical temperature T clp also. Its metastable solidification from temperatures above T clp leads to the formation of the perovskite at around 1550°C.