Inversion of the direction of the solid-liquid interface on the Czochralski growth of GGG crystals

Abstract

In the process of the crystal growth of Gd 3Ga 5O 12 by the Czochralski method, the shape of the solid-liquid interface drastically changes from convex to concave toward the melt at a certain crystal diameter under a constant seed rotation rate condition. It is due to the remelting of the old crystal and is related to the balance between a natural convection and a forced one caused by crystal rotation. The relationship between the conditions of the inversion and the growth parameters have been examined by growing the crystals under various conditions. The inversion diameter which gives the inversion of the interface was expressed as (Re η/ϱ) 1 2 ω s -1 2 by introducing the Reynolds number Re.