[14a-F203-1~13] 15.1 Bulk crystal growth

[14a-F203-8] Effect of molten-zone instability on the impurity partitioning during FZ growth

Yutaroh Takehara¹, Chihiro Koyama¹, 〇Satoshi Uda¹ (1.IMR Tohoku Univ.)

Keywords:floating zone method, impurity, Pfann's equation

It is thought that the crystal composition matches the source composition during the steady-state growth via a FZ method. However, it is not always true. We have investigated the so-called Pfann's equation for the growth of Nb-doped TiO₂ crystal and set up the modified equations for the case of (1) the melt quantity of the molten zone is constant during growth and (2) the melt quantity is lineally variable with the grown length. We found that the crystal composition attains a certain value during the steady-state growth, however, it is not necessarily the same as that of the source material when the quantity of the molten zone lineally changes during growth.