Structural High-Entropy FePt Alloy Nanoparticles Enabled Fast Magnetization Dynamics

作者：Wanqing Li, Zhengdong Cheng, Xiuyu Wang · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c16751 · 被引用次数：3 · 研究领域：Topological Materials and Phenomena、Magnetic and transport properties of perovskites and related materials、High Entropy Alloys Studies

While interfacial chiral symmetry breaking enables magnetization control in two-dimensional materials, achieving precise modulation in ultrasmall zero-dimensional magnetic nanoparticles remains challenging due to spin scattering lengths comparable to particle dimensions. Here, we establish a crystal symmetry-breaking paradigm using structural high-entropy FePt nanoparticles (merely 4 nm)─featuring chemically disordered face-centered cubic (FCC) phases and quadruple grain boundaries─to manipulate zero-dimensional magnetization dynamics. These nanoparticles exhibit coexisting short-range FCC structural order (separated by the grain boundary network) with atomic-scale chemical disorder. This unique synergy collectively suppresses orbital hybridization and decoheres spin–orbit coupling, drastically reducing magnetic anisotropy ( K = 4 × 10 5 J m –3, merely 4% of FCT-FePt) while enhancing magnetic susceptibility by an order of magnitude. Consequently, equilibrium magnetic relaxation accelerates significantly (τ fwhm = 79.4 ns), demonstrating efficient magnetization control tailored to nanoscale applications.