Crystal field excitation in the chiral helimagnet YbNi3Al9
Crystal field excitation in the chiral helimagnet YbNi3Al9
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DOI：
10.1103/physrevb.107.104425
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发表时间：
2023-03
影响因子：
3.7
通讯作者：
Mitsuru Tsukagoshi;Suguru Kishida;Kenshin Kurauchi;D. Ito;Koya Kubo;T. Matsumura;Y. Ikeda;Shota Nakamura;S. Ōhara
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文献类型：
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作者：
Mitsuru Tsukagoshi;Suguru Kishida;Kenshin Kurauchi;D. Ito;Koya Kubo;T. Matsumura;Y. Ikeda;Shota Nakamura;S. Ōhara
用非弹性中子散射方法确定了单轴手征螺旋磁体YbNi 3Al 9的晶场能级图，该晶体通过Cu替代Ni而呈现手征磁孤子晶格态.基态和第一激发态双峰之间的距离为44 K，简单地表示为$\alpha|\pm 7/2\rangle + \beta|\mp 5/2\rangle$，其中$\alpha$和$\beta$几乎等于$\pm 1/\sqrt{2}$。当激发能级在高温和高磁场下被填充时，晶场各向异性的易轴是c轴。另一方面，在低温和低磁场下，只有地偶极子占据，磁性由易面各向异性描述，它可以被视为具有各向异性g因子的$S=1/2$系统，$g_{xy}=3.02$和$g_z=1.14$。还讨论了轨道相关的交换相互作用，以解释磁化率的温度依赖性基于这个水平计划。
Crystal field level scheme of a uniaxial chiral helimagnet YbNi$_3$Al$_9$, exhibiting a chiral magnetic soliton lattice state by Cu substitution for Ni, has been determined by inelastic neutron scattering. The ground and the first excited doublets are separated by 44 K and are simply expressed as $\alpha|\pm 7/2\rangle + \beta |\mp 5/2\rangle$ with $\alpha$ and $\beta$ nearly equal to $\pm 1/\sqrt{2}$. The easy axis of the crystal field anisotropy is the $c$ axis when the excited levels are populated at high temperatures and high magnetic fields. On the other hand, the magnetism at low temperatures and low magnetic fields, where only the ground doublet is populated, is described by an easy plane anisotropy which may be treated as an $S=1/2$ system with an anisotropic $g$-factor, $g_{xy}=3.02$ and $g_z=1.14$. An orbital dependent exchange interaction is also discussed to explain the temperature dependence of the magnetic susceptibility based on this level scheme.