Bonding Heterogeneity and Nanoprecipitation on Substituting the Anionic Framework in Mg₃Sb₂ for p‐Type Zintl Thermoelectrics

Zintl Thermoelectrics Designing Zintl compounds with complex structures and heavy elements enables bonding heterogeneity, inducing lattice anharmonicity and low thermal conductivity. In article number 2400632, Takao Mori and Nagendra Singh Chauhan explore alloying-driven bonding heterogeneity in α-Mg3(Sb, Bi)2, revealing local atomic ordering and heterogeneous interfaces in Mg3(Sb1−2xBixSnx)2. Alloying triggers partial phase transitions, with a cubic Mg2Sn nanophase emerging at x ≥ 0.1. Optimized nanocomposites achieve zT ∼ 0.25 at 673 K, highlighting the role of anionic sites in structural and functional properties.