笼状铁磁体EuTi3Bi4中与易磁轴解耦的磁畴织构切换
Decoupled domain-texture switching from magnetic easy axis in kagome ferromagnet EuTi3Bi4
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中文总结 AI 辅助
该研究在笼状铁磁体EuTi3Bi4中发现无需重定向易磁轴，仅通过调节面内各向异性相互作用的竞争即可实现磁畴织构的切换，为宏观磁织构操控提供了低能耗新途径。
中文摘要 AI 辅助
磁各向异性定义了磁性材料的易磁轴，并决定了其磁畴的空间排列。迄今为止，各向异性工程的研究重点是重新定向易磁轴或调节各向异性能，这两种操作都需要大量能量输入。本文中，我们在笼状铁磁体EuTi3Bi4晶体中观测到，无需重新定向易磁轴即可实现磁畴织构的切换。利用低温磁力显微镜，我们观测到随着温度变化，磁畴的优选取向从a轴切换至b轴，且该切换也可通过面外磁场重置触发。磁化测量和密度泛函理论计算证实存在稳定的c轴易磁化方向，排除了常规的自旋重取向转变。相反，织构切换由磁各向异性能量曲面的面内变化的温度依赖性主导，该依赖性源于两种具有不同衰减速率的竞争相互作用：单离子各向异性倾向于a轴取向的自旋分量，而近邻各向异性交换倾向于b轴取向的自旋分量。此外，机械剥离的EuTi3Bi4薄片的临界切换温度显著升高。我们的发现表明，通过调节面内各向异性相互作用的竞争，可有效操控宏观磁织构，且无需承担重新定向易磁轴的能量成本。
英文摘要
Magnetic anisotropy defines the easy axis of a magnetic material and governs the spatial arrangement of its domains. To date, anisotropy engineering has focused on reorienting the easy axis or tuning the anisotropy energy, both of which demand substantial energy input. Here, we demonstrate that magnetic domain textures can be switched without reorienting the easy axis, as observed in a kagome ferromagnet EuTi3Bi4 crystal. Using low-temperature magnetic force microscopy, we observe that the preferred orientation of magnetic domains switches from the a-axis to the b-axis upon temperature variation, and that this switching can also be triggered by an out-of-plane magnetic-field reset. Magnetization measurements and density functional theory calculations confirm a robust c-axis easy magnetization, ruling out a conventional spin-reorientation transition. Instead, the texture switching is governed by the temperature dependence of the in-plane variation of the Magnetic anisotropy energy landscape, which arises from two competing interactions with different decay rates: single-ion anisotropy favors a-oriented spin components, while nearest-neighbor anisotropic exchange favors b-oriented ones. Furthermore, the critical switching temperature is substantially elevated in a mechanically exfoliated EuTi3Bi4 flake. Our findings establish that macroscopic magnetic textures can be effectively manipulated by tuning the competition between in-plane anisotropic interactions, without the energy cost of reorienting the easy axis.
