SiC-B₄C composites for synergistic enhancement of thermoelectric property

SiC-B₄C composites were fabricated by hot pressing of β-SiC and B₄C powder mixture. The Seebeck coefficient was determined at 300-900 °C in air. The SiC-B₄C composites exhibited very high value. Especially, the Seebeck coefficient of SiC-30wt.%B₄C composite was about 700 μ/K at 900 °C. Such a high Seebeck coefficient is very attractive. Monolithic SiC and B₄C had the Seebeck coefficient of 100-400 μV/K, respectively. In SiC-B₄C composite system, the Seebeck coefficient had been increased by the combination of SiC and B₄C. In TEM observation, many stacking faults were observed in SiC-B₄C composites. The presence of stacking faults may be one reason for the high Seebeck coefficient of SiC-B₄C composite.