Competing spin modulations in the magnetically frustrated semimetal EuCuSb
Competing spin modulations in the magnetically frustrated semimetal EuCuSb
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磁阻半金属 EuCuSb 中的竞争自旋调制
DOI：
10.1103/physrevb.102.174425
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发表时间：
2020
影响因子：
3.7
通讯作者：
Ishiwata Shintaro
中科院分区：
文献类型：
--
作者：
Takahashi Hidefumi;Aono Kai;Nambu Yusuke;Kiyanagi Ryoji;Nomoto Takuya;Sakano Masato;Ishizaka Kyoko;Arita Ryotaro;Ishiwata Shintaro
通过对单晶样品的磁化、电阻率和中子衍射测量，研究了具有六边形层状结构的流动磁体EuCuSb的竞争磁基态。通过能带计算和角分辨光电子能谱证实，EuCuSb具有三维半金属能带结构，与顺磁状态下近乎各向同性的金属电导率一致。然而，在反铁磁转变温度（8.5 K）以下，电阻率，特别是沿六方轴的电阻率显著增加。这意味着与导电电子耦合的各向异性磁有序的出现。中子衍射测量表明，Eu自旋在每一层内按铁磁顺序排列，沿着下面的六角形轴共线调制（上-上-下-下），随后在（6 K）以下部分出现螺旋自旋调制。基于对具有磁滞行为的异常磁电阻的观察，我们讨论了具有中心对称结构的受挫类海森堡自旋系统固有的基态竞争性质。
The competing magnetic ground states of the itinerant magnet EuCuSb, which has a hexagonal layered structure, were studied via magnetization, resistivity, and neutron-diffraction measurements on single-crystal samples. EuCuSb has a three-dimensional semimetallic band structure as confirmed by band calculation and angle-resolved photoelectron spectroscopy, consistent with the nearly isotropic metallic conductivity in the paramagnetic state. However, below the antiferromagnetic transition temperature of(8.5 K), the resistivity, especially along the hexagonal axis, increases significantly. This implies the emergence of anisotropic magnetic ordering coupled to the conducting electrons. Neutron-diffraction measurements show that the Eu spins, which order ferromagnetically within each layer, are collinearly modulated (up-up-down-down) along the hexagonal axis below, followed by the partial emergence of helical spin modulation below(6 K). Based on the observation of anomalous magnetoresistance with hysteretic behavior, we discuss the competing nature of the ground state inherent in a frustrated Heisenberg-like spin system with a centrosymmetric structure.