Effect of mangetic field on macrosegregation in (Bi, Sb)_2Te_3

摘要

A thermoelectric materials (Bi_0.25 Sb_0.75)_2Te_3 was grown by a vertical gradient freezing technique in high magnetic fields of up to 8 T. The radial distribution of composition showed macrosegregation when the specimens were solidified in the magnetic field. The radial segregation increased with increasing intensity of the magnetic field. On the other hand, the longitudinal distribution for both the specimens under 0 T and 8 T had a variation at the initial transient, but no effect of the magnetic field on the composition distribution was observed.