|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Alloys and Compounds for Thermoelectric and Solar Cell Applications X
||Theory of Huge Thermoelectric Effect Based on Magnon Drag Mechanism: Application to Thin-film Heusler Alloy
||Masao Ogata, Hiroyasu Matsuura, Takao Mori, Ernst Bauer
|On-Site Speaker (Planned)
Recently, a thin-film Heusler alloy, Fe_2V_0.8W_0.2Al has attracted extensive attention because it shows a huge figure of merit (ZT~5) near the room temperature, derived from an unprecedentedly huge power factor, which we propose is actually related to the magnetism in this material. To understand the high thermoelectric performance in this thin-film Heusler alloy, we study the magnon drag effect, generated by the tungsten-based impurity band, as a possible source of this enhancement in analogy to the phonon drag observed in FeSb_2. Assuming that the thin-film Heusler alloy has a conduction band integrating with the impurity band, originated by the tungsten substitution, we derive the electrical conductivity based on the self-consistent t-matrix approximation and the thermoelectric conductivity due to magnon drag based on the linear response theory. We show that the origin of the huge thermoelectric properties is likely due to the magnon drag related with the tungsten-based impurity band.
||Modeling and Simulation, Magnetic Materials, Thin Films and Interfaces