Interaction of spin-orbital-lattice degrees of freedom - vibrionic state of corner-sharing-tetrahedral spin frustrated system HoBaFe4O7 by dynamical Jahn-Teller Effect -
Interaction of spin-orbital-lattice degrees of freedom - vibrionic state of corner-sharing-tetrahedral spin frustrated system HoBaFe4O7 by dynamical Jahn-Teller Effect -
复制标题
自旋轨道晶格自由度的相互作用 - 动态 Jahn-Teller 效应的共享角四面体自旋受挫系统 HoBaFe4O7 的振动状态 -
DOI：
10.1103/physrevb.95.104413
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
K. Nakajima and M. Sato
中科院分区：
文献类型：
--
作者：
K. Kamazawa;M. Ishikado;S. Ohira-Kawamura;Y. Kawakita;K. Kakurai;K. Nakajima and M. Sato
粉末非弹性中子散射研究（HBFO）揭示了与几何自旋挫折的特征磁激发。在能量和波矢空间中观察到几个离散能量的无色散激发。其中一些可以归因于八面体对称中的晶体场激发，但其他的则由具有轨道-自旋耦合的动态Jahn-Teller效应的振动态来解释，表明自旋、轨道和晶格自由度之间的相互作用。反铁磁HBFO晶格具有立方对称性，且均为数比为3：1的共角四面体。即使是四面体对称的Jahn-Teller活性离子，该系统在研究的最低温度（4 K）下也没有表现出任何静态晶格畸变。通过考虑自旋-轨道-晶格自由度之间的动力学相互作用可以理解所观察到的激发，表明由于阻挫效应引起的自旋涨落引起动态Jahn-Teller效应，尽管在大多数情况下，Jahn-Teller活性离子在磁性氧化物系统中具有静态Jahn-Teller效应。
A powder inelastic neutron-scattering study of(HBFO) revealed characteristic magnetic excitations associated with geometrical spin frustration. Dispersionless excitations in energy () and wave-vector () space are observed at several discrete energies. Some of them can be attributed to crystal-field excitations ofin octahedral symmetry, but the others are explained instead by the vibronic state of thedynamical Jahn-Teller effect with orbit-spin coupling, indicating interaction among the spin, the orbital, and the lattice degree of freedom. The antiferromagnetic HBFO lattice has cubic symmetry, and bothandreside on corner-sharing tetrahedra with a number ratio of 3:1. Even thoughis a Jahn-Teller active ion in tetrahedral symmetry, the system does not exhibit any static lattice distortion to the lowest temperature studied (4 K). The observed excitations can be understood by considering the dynamical interaction among spin-orbital-lattice degrees of freedom, indicating that spin fluctuation due to the frustration effect induces the dynamical Jahn-Teller effect, although in most cases a Jahn-Teller active iontakes the static Jahn-Teller effect in a magnetic oxide system.