Magnetic 2D materials enable interesting tuning options of magnetism. As an example, the van der Waals material FePS₃, a zig-zag-type intralayer antiferromagnet, exhibits very strong magnetoelastic coupling due to the different bond lengths along different ferromagnetic and antiferromagnetic coupling directions enabling elastic tuning of magnetic properties. The likely cause of the length change is the intricate competition between direct exchange of the Fe atoms and superexchange via the S and P atoms. To elucidate this interplay, we study the band structure of exfoliated FePS₃ by μm scale ARPES (angular resolved photoelectron spectroscopy), both, above and below the Néel temperature T_N. We found three characteristic changes across T_N. They involve S 3p-type bands, Fe 3d-type bands and P 3p-type bands, respectively, as attributed by comparison with density functional theory calculations (DFT + U). This highlights the involvement of all the atoms in the magnetic phase transition providing independent evidence for the intricate exchange paths.

中文翻译：

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识别 FePS3 在反铁磁相变过程中的能带结构变化


磁性 2D 材料可实现有趣的磁性调谐选项。例如，范德华材料 FePS₃ 是一种锯齿形层内反铁磁体，由于沿不同铁磁和反铁磁耦合方向的键长不同，因此表现出非常强的磁弹性耦合，从而能够对磁性能进行弹性调节。长度变化的可能原因是 Fe 原子的直接交换与通过 S 和 P 原子的超交换之间的复杂竞争。为了阐明这种相互作用，我们通过 μm 尺度 ARPES（角度分辨光电子能谱）研究了剥离的 FePS₃ 的能带结构，两者均高于和低于 Néel 温度 T_N。我们发现 T_N 的 3 个特征性变化。它们分别涉及 S 3p 型带、Fe 3d 型带和 P 3p 型带，通过与密度泛函理论计算 （DFT + U） 进行比较得出。这突出了所有原子都参与磁相变，为错综复杂的交换路径提供了独立的证据。