The magnetic anisotropy determines the equilibrium orientation of the magnetization in a ferromagnet. In Mn-based inverse tetragonal Heusler compounds, a large uniaxial anisotropy makes these materials excellent candidates for both spin-transfer-torque and skyrmionic devices. Here, we present systematic investigations of the magnetocrystalline anisotropies in Mn_xPtSn films (x = 1.0–1.6). We find that the Mn_xPtSn films, grown by magnetron sputtering on MgO substrates, show a structural transition between x = 1.0 and 1.2 from cubic to tetragonal, where the tetragonal structure shows a twinned in-plane c-axis orientation. From ferromagnetic resonance measurements, we determine the out-of-plane and in-plane uniaxial anisotropies, taking into account the particular structural properties of the films. We find a strong dependence of the uniaxial anisotropies on the Mn concentration, as well as on structural distortions due to the lattice-matched growth. From temperature-dependent ferromagnetic resonance measurements, we infer the evolution of the in-plane uniaxial anisotropy and observe the presence of additional magnetic interactions and magnetization relaxation mechanisms around the spin reorientation transition.

中文翻译：

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MnxPtSn薄膜中的磁晶各向异性

磁各向异性决定了铁磁体中磁化强度的平衡取向。在基于 Mn 的反四方 Heusler 化合物中，大的单轴各向异性使这些材料成为自旋转移扭矩和 Skyrmionic 器件的绝佳候选材料。在这里，我们对Mn _x PtSn薄膜（x = 1.0-1.6）中的磁晶各向异性进行系统研究。我们发现通过磁控溅射在 MgO 衬底上生长的 Mn _x PtSn 薄膜显示出x = 1.0 和 1.2 之间从立方到四方的结构转变，其中四方结构显示出孪晶面内c- 轴方向。根据铁磁共振测量，我们确定面外和面内单轴各向异性，同时考虑到薄膜的特定结构特性。我们发现单轴各向异性对 Mn 浓度以及由于晶格匹配生长引起的结构扭曲有很强的依赖性。从依赖于温度的铁磁共振测量中，我们推断出面内单轴各向异性的演变，并观察到在自旋重定向转变周围存在额外的磁相互作用和磁化弛豫机制。