High Thermoelectric Figure of Merit of Full‐Heusler Ba2AuX (X = As, Sb, and Bi). Issue 6 (1st April 2020)

• Record Type: Journal Article
• Authors: Ma, Jinlong; Nissimagoudar, Arun S.; Wang, Shudong; Li, Wu
• Is Part Of: Physica status solidi. Volume 14:Issue 6(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-01
• Subjects: electrical transport -- first principles -- full-Heuslers -- thermoelectrics; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202000084
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Herein, an unprecedentedly high thermoelectric figure of merit ( ZT ) in full‐Heusler compounds of Ba2 AuX (X = As, Sb, and Bi) is predicted by performing first‐principles calculations combined with parameter‐free Boltzmann transport equations. It is found that the ZT can reach up to 5 and 3 at 800 K in n‐ and p‐type systems, respectively, and can be as high as 1.7 and 1.0 at room temperature. The high ZT is attributed to the high power factor coupled with low thermal conductivity. The spin–orbit coupling (SOC) is necessarily considered because the exclusion of SOC significantly overestimates the electron mobility but underestimates the hole mobility of Ba2 AuBi. The Lorenz number is found to exhibit an expected monotonical increase with carrier concentration, in contrast to the reported literature results. Abstract : Full‐Heusler Ba2 AuX (X = As, Sb, and Bi) possesses a superior thermoelectric figure of merit in both n‐ and p‐types above room temperature, up to 5 and 3 at 800 K, and values of 1.7 and 1.0 at 300 K, respectively. It indicates great advantage to form a one‐material thermoelectric system and shows good performance in a wide temperature range.