AI 中文总结
本研究通过厚度调控在范德华铁磁体Fe$_3$GaTe$_2$中诱导出室温近1 T的巨矫顽力，揭示了磁化反转机制的厚度依赖转变，为开发不含稀土的高性能硬磁材料提供了新方向。
AI 中文摘要
具有强各向异性和高居里温度的永磁体是现代信息与能源技术的基础，但不含稀土的替代材料仍十分有限。本研究展示，通过机械剥离的厚度调控可在范德华铁磁体Fe$_3$GaTe$_2$中诱导出硬磁行为：体相晶体的居里温度高于350 K，但室温矫顽力可忽略；当厚度减薄至100 nm以下时，矫顽场显著增强，室温下沿面内方向的矫顽场接近1 T，与传统硬磁体的数值相当。微磁分析表明，这种厚度依赖的磁化反转机制转变源于有效各向异性增大与畴形成受抑，从体相的畴介导过程转变为薄层的准相干旋转，无需化学改性即可调控磁硬度。结合高饱和磁化强度与稳定的室温性能，Fe$_3$GaTe$_2$成为自旋电子学应用中极具潜力的不含稀土材料，其层状结构还可集成到范德华异质结构中，大的面内矫顽力可稳定磁态，为高密度非易失性存储器和基于畴壁的器件提供可能。
英文摘要
Permanent magnets with strong anisotropy and high coercivity underpin modern information and energy technologies, yet rare-earth-free alternatives remain limited. Here, we show that thickness engineering via mechanical exfoliation induces hard magnetic behavior in the van der Waals ferromagnet Fe$_3$GaTe$_2$. Bulk crystals exhibit Curie temperatures above 350 K but negligible room-temperature coercivity. When thinned below 100 nm, the coercive field is dramatically enhanced, reaching nearly 1 T at room temperature for in-plane fields which is comparable to values of conventional hard magnets. Micromagnetic analysis reveals a crossover in magnetization reversal from domain-mediated processes in bulk samples to quasi-coherent rotation in thin flakes, driven by increased effective anisotropy and suppressed domain formation. This thickness-dependent transition enables tuning of magnetic hardness without chemical modification. Combined with high saturation magnetization and robust room-temperature performance, Fe$_3$GaTe$_2$ emerges as a promising rare-earth-free material for spintronic applications. Its layered structure further allows integration into van der Waals heterostructures, where large in-plane coercivity can stabilize magnetic states against perturbations and interlayer coupling, offering potential for high-density nonvolatile memory and domain-wall-based devices.
Comments5 figures, plus Supplementary information, including 6 supplementary figures
Journal refAdvanced Electronic Materials 2026
