Designing vacancy-filled Heusler thermoelectric semiconductors by the Slater-Pauling rule. (July 2022)

• Record Type: Journal Article
• Authors: Zhang, Jiayang; Dong, Zirui; Tan, Shihua; Li, Yue; Zhang, Jiye; Zhang, Wenqing; Luo, Jun
• Is Part Of: Materials today energy. Volume 27(2022)
• Publication Date: 2022-07
• Subjects: Valence electron rule -- Heusler alloys -- Thermoelectric materials -- HfRu1+xSb -- Vacancy filling; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2022.101035
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Heusler alloys with six valence electrons per atom on average are Slater-Pauling semiconductors. The half-Heusler semiconductor exhibits excellent thermoelectric properties due to its specific electronic band structure. In this work, we report on the design and discovery of HfRu1+ x Sb-based semiconductors using the Slater-Pauling rule. According to the Slater-Pauling rule, the composition HfRu1.5 Sb with 21 valence electrons is a stable semiconductor, agreeing well with our theoretical calculation. Experiments reveal that the HfRu1.6 Sb sample is nearly an intrinsic semiconductor, which deviates slightly from the Slater-Pauling rule and theoretical calculation. Meanwhile, both p-type ( x < 0.6) and n-type ( x > 0.6) conductions can be realized in the HfRu1+ x Sb samples by adjusting the Ru content, and the thermoelectric properties of the HfRu1+ x Sb samples can be further improved by isoelectronic alloying on the Hf site with Ti. The dimensionless thermoelectric figure of merit zT of p-type HfRu1.4 Sb semiconductor is ∼0.37 at 973 K, and the Ti0.9 Hf0.1 Ru1.4 Sb sample reaches a zT value about 0.50 at 973 K, achieving an increase of 30%. Our work shows that more vacancy-filled Heusler semiconductors with tunable and promising thermoelectric properties could be designed based on the Slater-Pauling rule. Graphical abstract: Image 1 Highlights: Vacancy-filled Heusler semiconductors HfRu1+ x Sb are designed by the Slater-Pauling rule. By adjusting the Ru content, both p-type and n-type thermoelectric materials can be realized in HfRu1+ x Sb. The thermoelectric properties of the HfRu1+ x Sb samples are optimized by isoelectronic alloying on the Hf site with Ti. The Ti0.9 Hf0.1 Ru1.4 Sb sample reaches a zT value about 0.50 at 973 K.