Microstructure and thermoelectric properties of β-FeSi2 ceramics fabricated by hot-pressing and spark plasma sintering

► With increasing hot-pressing (HP) temperature, the thermoelectric figure of merit of β-FeSi2 ceramics is improved slightly. ► The grain size of the sample sintered by the spark plasma sintering (SPS) process is smaller than that by the HP process. ► The SPS sample shows excellent thermoelectric performance attributed to low thermal conductivity.