Microstructure and thermoelectric properties of B-C-Y system composites

B-C-Y system composites were prepared by arc-melting using B₄ C, YB₆ and B powders. The two-phase region of B₄ C+YB₆ was a quasi-binary eutectic system whose eutectic composition was about 40 mol% YB₆. In the B₄C-YB ₆ system composites, with increasing YB₆ content, the electrical conductivity and thermal conductivity increased, but the Seebeck coefficients and dimensionless figure-of-merit (ZT) decreased. The B₄C-YB₆ composites containing a small amount of YB₆ had larger α and ZT values than those of B₄ C. The greatest ZT value obtained in the B-C-Y system was 0.54 at T=1100 K