The effect of titanium diboride addition on the thermoelectric properties of β-FeSi2 semiconductors

β-FeSi2–TiB2 composites with various amounts of TiB2, from 0 up to 30 vol%, were prepared by hot pressing. The electrical and thermal conductivities, and the Seebeck coefficient were measured as a function of temperature. The results show that the thermal and electrical transport behavior of the composites is different as the volume fraction of TiB2 is below and above about 0.255. A 5 vol% TiB2 added sample has higher figure of merit than one without TiB2 for temperatures above 650 K. The influence of an additional phase, ε-FeSi, formed during the hot pressing, on the thermoelectric properties of the β-FeSi2–TiB2 composites was also discussed.