Thermoelectric Properties of Bulk Yttrium Silicide (YSi2) Fabricated by Arc Melting and Spark Plasma Sintering

Yttrium silicide (YSi 2 ) nanoparticles in SiGe are reported to enhance the thermoelectric figure‐of‐merit ( ZT ) to the recorded value (≈1.81). However, the thermoelectric properties of bulk YSi 2 has never been reported. In this work, the thermoelectric properties of YSi 2 is studied for the first time. The bulk YSi 2 is fabricated by arc melting highly pure Si and Y raw materials. The ingot is crushed to powder and compacted to form a highly dense pellet by spark plasma sintering. By optimizing the processing parameters, the single phase with the AlB 2 ‐type structure ( P 6/ mmm ) is formed. The Hall measurements show that YSi 2 exhibit a metallic‐like behavior with a very high electron concentration. This result in the thermoelectric properties with a very large electrical conductivity (≈18 × 10 5  Ω −1  m −1 ) but a small Seebeck coefficient (−26 µV K −1 ) at room temperature, and decrease with temperature. The thermal conductivity is around 14–19 W m −1  K −1 for all temperature range. The maximum ZT value is 0.026 at 423 K.