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

Abstract

Yttrium silicide (YSi2) 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 YSi2 has never been reported. In this work, the thermoelectric properties of YSi2 is studied for the first time. The bulk YSi2 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 AlB2‐type structure (P6/mmm) is formed. The Hall measurements show that YSi2 exhibit a metallic‐like behavior with a very high electron concentration. This result in the thermoelectric properties with a very large electrical conductivity (≈18 × 105 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.