A Kagome Metallic Composite Realizes Mechanically Axial Zero Thermal Expansion up to 800 K

Abstract Manipulating the crystal structure and microstructure is fundamentally paramount for designing advanced materials with enhanced functionalities. Kagome‐lattice metals attracted considerable attention due to desirable electronic and magnetic properties but are rarely considered for application as structural materials. In this study, a concept of kagome composite is proposed to realize mechanically zero thermal expansion (ZTE) alloy over a wide temperature window, exemplified by the Lu‐Fe‐Co ternary alloys prepared by two‐step synthesis. Using magnetic Co doping, the kagome lattice magnetic order is stabilized in the parent hexagonal Lu 2 Fe 17 structure, and its thermal expansion regulated simultaneously. By in situ precipitation of the α‐(Fe/Co) phase in the matrix, a soft/hard heterogeneous structure emerges and an ultra‐wide temperature window axial ZTE composite ( α l = +0.98 × 10 −6 K −1 , 110–800 K) with good compressive strength (1.11 GPa) is achieved. This work opens up the prospect of kagome intermetallic composite in the integration of structure and function.