抄録
The fragmentation of the faceted dendrite of B-doped Si solidified from the undercooled melt was investigated using an electromagnetic levitator. The ＜110＞ dendrites, which grew at Δ T＜ ～ 100 K, never fragmented because they were composed of {111} planes with a lowest interface energy. On the other hand, the ＜100＞ dendrites, which grew at Δ T＞～ 100 K showing fourfold axial symmetry, broke up into small pieces at undercoolings of more than 200 K. It was suggested that the capillary force acts on the interface with a relatively high energy to break up the dendrite into small pieces, since the ＜100＞ dendrite is composed of {110} and {100} planes with interface energies larger than that of the {111} plane. Moreover, striations of concentric circles formed by the segregation of B revealed that the remaining melt solidifies from the surface toward the center to engulf the fragmented dendrites. This suggests that the ＜100＞ dendrites fragmented during and/or after the recalescence.
