A facile colloidal solution method has been developed for the fast, scalable synthesis of orthorhombic@cubic core–shell nonstoichiometric Cu₅FeS₄ icosahedral nanoparticles. Such nanoparticles contain high‐density twin boundaries in the form of fivefold twins. Spark plasma sintering consolidates the nanoparticles into nanostructured pellets, which retain high‐density twin boundaries and a tuned fraction of the secondary phase Fe‐deficient cubic Cu₅FeS₄. As a result, the thermal and electrical transport properties are synergistically optimized, leading to an enhanced zT of ≈0.62 at 710 K, which is about 51% higher than that of single‐phase Cu₅FeS₄. This study provides an energy‐efficient approach to realize twin engineering in nonstoichiometric Cu₅FeS₄ nanomaterials for high‐performance thermoelectrics.

中文翻译：

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溶液合成的非化学计量Cu5FeS4二十面体纳米颗粒的双工程技术，可增强热电性能

已经开发了一种简便的胶体溶液方法，用于快速，可扩展地合成正交晶体@立方核-壳非化学计量的Cu ₅ FeS ₄二十面体纳米粒子。此类纳米颗粒包含五重孪晶形式的高密度孪晶边界。火花等离子体烧结将纳米颗粒固结成纳米结构的颗粒，该颗粒保留了高密度孪晶界和次级相中缺铁立方晶Cu ₅ FeS _{4的一部分}。结果，协同优化了热和电传输特性，从而在710 K时的zT增强了≈0.62，比单相Cu ₅ FeS ₄的zT高约51％。。这项研究提供了一种高效节能的方法，可以在高性能热电学的非化学计量Cu ₅ FeS ₄纳米材料中实现双工程。