Interplanar Ferromagnetism Enhanced Ultrawide Zero Thermal Expansion in Kagome Cubic Intermetallic (Zr,Nb)Fe<sub>2</sub>
Yanming Sun, Yili Cao, Shixin Hu, Maxim Avdeev, Chin‐Wei Wang, Sergii Khmelevskyi, Yang Ren, Saul H. Lapidus, Xin Chen, Qiang Li, Jinxia Deng, Jun Miao, Kun Lin, Xiaojun Kuang, Xianran Xing
Abstract
A cubic metal exhibiting zero thermal expansion (ZTE) over a wide temperature window demonstrates significant applications in a broad range of advanced technologies but is extremely rare in nature. Here, enabled by high-temperature synthesis, we realize tunable thermal expansion via magnetic doping in the class of kagome cubic ( Fd -3 m ) intermetallic (Zr,Nb)Fe 2 . A remarkably isotropic ZTE is achieved with a negligible coefficient of thermal expansion (+0.47 × 10 –6 K –1 ) from 4 to 425 K, almost wider than most ZTE in metals available. A combined in situ magnetization, neutron powder diffraction, and hyperfine Mössbauer spectrum analysis reveals that interplanar ferromagnetic ordering contributes to a large magnetic compensation for normal lattice contraction upon cooling. Trace Fe-doping introduces extra magnetic exchange interactions that distinctly enhance the ferromagnetism and magnetic ordering temperature, thus engendering such an ultrawide ZTE. This work presents a promising ZTE in kagome metallic materials.