High-performance ZrNiSn-based half-Heusler thermoelectrics with hierarchical architectures enabled by reactive sintering

作者：Xin Ai, Yu Wu, Haiyan Lyu, Lars Giebeler, Wenhua Xue, A. V. Sotnikov, Yumei Wang, Qihao Zhang, Denys Makarov, Yuan Yu, G. Jeffrey Snyder, Kornelius Nielsch, Ran He · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-61868-x · 被引用次数：29 · 研究领域：Advanced Thermoelectric Materials and Devices、Heusler alloys: electronic and magnetic properties、Thermal properties of materials

Abstract Half-Heusler compounds are promising thermoelectric materials for high-temperature applications, yet their performance is limited by high lattice thermal conductivity. Here, we present an alternative approach to synthesize ZrNiSn-based half-Heusler compounds with hierarchical architectures across multiple length scales. By utilizing short-duration mechanical alloying to produce nonequilibrium precursors, followed by reactive sintering, we enable precise control over phase composition and microstructural features. This approach results in multi-scale architectures comprising interstitial defects, grain boundaries, nanoprecipitates, and pores, enabling strong phonon scattering. The optimized Zr 0.75 Hf 0.25 NiSn 0.99 Sb 0.01 alloy exhibits a lattice thermal conductivity as low as 1.9 W m −1 K −1 and a high power factor of 50 µW cm −1 K −2 , yielding an impressive dimensionless figure of merit ( zT ) of 1.33 at 873 K. This performance surpasses that of ZrNiSn-based compounds synthesized via conventional methods such as arc melting and solid-state reaction. Our method, distinguished from conventional melting synthesis approaches through its simplicity, cost-effectiveness, and scalability, provides a versatile framework for achieving efficient hierarchical phonon scattering while preserving high carrier mobility in half-Heusler compounds and highlights the potential of reactive sintering for advancing thermoelectric materials.