Affiliation:
1. Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'an Shaanxi 710049 China
2. Key Laboratory of Neutron Physics Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang Sichuan 621999 China
3. School of Materials Science and Engineering Sichuan University Chengdu Sichuan 610065 China
4. CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Material Technology and Engineering Chinese Academy of Science Ningbo Zhejiang 315201 China
Abstract
AbstractRapid development of smart technologies poses a big challenge for magnetostrictive materials, which should not only permit isotropic and hysteresis‐free actuation (i.e., nonhysteretic volume change) in magnetic fields, but also have high strength and high ductility. Unfortunately, the magnetostriction from self‐assembly of ferromagnetic domains is volume‐conserving; the volume magnetostriction from field‐induced first‐order phase transition has large intrinsic hysteresis; and most prototype magnetostrictive materials are intrinsically brittle. Here, a magnetic high‐entropy alloy (HEA) Fe35Co35Al10Cr10Ni10 is reported that can rectify these challenges, exhibiting an unprecedented combination of large nonhysteretic volume magnetostriction, high tensile strength and large elongation strain, over a wide working temperature range from room temperature down to 100 K. Its exceptional properties stem from a dual‐phase microstructure, where the face‐centered cubic (FCC) matrix phase with nanoscale compositional and structural fluctuations can enable a magnetic‐field‐induced transition from low‐spin small‐volume state to high‐spin large‐volume state, and the ordered body‐centered cubic (BCC) B2 phase contributes to mechanical strengthening. The present findings may provide insights into designing unconventional and technologically important magnetostrictive materials.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China