论文标题
非中心对称四方抗铁磁铁Euptsi $ _ {3} $的磁性特性
Magnetic properties of the noncentrosymmetric tetragonal antiferromagnet EuPtSi$_{3}$
论文作者
论文摘要
我们报告了一项对非中心稀有地球化合物Euptsi $ _ {3} $通过光学浮动区域生长的单晶的全面研究。磁化，AC易感性和比热的测量始终建立局部EU $^{2+} $矩的局部反铁磁性顺序，低于Néel温度$ t $ t _ {\ MATHRM {n}} = 17〜 \ MATHRM {k} $，然后在$ T _ { 16〜 \ MATHRM {K} $。对于沿易于$ [001] $轴的磁场，磁相图由这两个阶段组成。对于在磁性基底平面中应用的磁场，在磁场下出现了两个附加阶段，其中平面各向异性弱，$ [100] $是最难的轴。在相变，磁性特性表现出差异和AC敏感性之间的滞后和差异，表明中尺度磁纹理的缓慢重新定位过程。一致地，零场中的粉末和单晶中子衍射标识了以$ 100〜 \ textrm {Å} $的长度比例调制的磁纹理，最有可能以Néel-type抗fiferromagnetic Cycloids的形式进行调节。
We report a comprehensive study of single crystals of the noncentrosymmetric rare-earth compound EuPtSi$_{3}$ grown by the optical floating-zone technique. Measurements of the magnetization, ac susceptibility, and specific heat consistently establish antiferromagnetic order of localized Eu$^{2+}$ moments below the Néel temperature $T_{\mathrm{N}} = 17~\mathrm{K}$, followed by a second magnetic transition at $T_{\mathrm{N1}} = 16~\mathrm{K}$. For a magnetic field along the easy $[001]$ axis, the magnetic phase diagram is composed of these two phases. For fields applied in the magnetically hard basal plane, two additional phases emerge under magnetic field, where the in-plane anisotropy is weak with $[100]$ being the hardest axis. At the phase transitions, the magnetic properties exhibit hysteresis and discrepancies between differential and ac susceptibility, suggesting slow reorientation processes of mesoscale magnetic textures. Consistently, powder and single-crystal neutron diffraction in zero field identify magnetic textures that are modulated on a length scale of the order of $100~\textrm{Å}$, most likely in the form of Néel-type antiferromagnetic cycloids.
