Vavilova Evgeniya, Salikhov Timur, Iakovleva Margarita, Vasilchikova Tatyana, Zvereva Elena, Shukaev Igor, Nalbandyan Vladimir, Vasiliev Alexander
Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS, 420029 Kazan, Russia.
3rd Physics Institute, University of Stuttgart, 70569 Stuttgart, Germany.
Materials (Basel). 2021 Nov 10;14(22):6785. doi: 10.3390/ma14226785.
The non-stoichiometric system LiNiSbO is a Li-deficient derivative of the zigzag honeycomb antiferromagnet LiNiSbO. Structural and magnetic properties of LiNiSbO were studied by means of X-ray diffraction, magnetic susceptibility, specific heat, and nuclear magnetic resonance measurements. Powder X-ray diffraction data shows the formation of a new phase, which is Sb-enriched and Li-deficient with respect to the structurally honeycomb-ordered LiNiSbO. This structural modification manifests in a drastic change of the magnetic properties in comparison to the stoichiometric partner. Bulk static (dc) magnetic susceptibility measurements show an overall antiferromagnetic interaction ( = -4 K) between Ni spins ( = 1), while dynamic (ac) susceptibility reveals a transition into a spin glass state at a freezing temperature ~ 8 K. These results were supported by the absence of the λ-anomaly in the specific heat (T) down to 2 K. Moreover, combination of the bulk static susceptibility, heat capacity and Li NMR studies indicates a complicated temperature transformation of the magnetic system. We observe a development of a cluster spin glass, where the Ising-like Ni magnetic moments demonstrate a 2D correlated slow short-range dynamics already at 12 K, whereas the formation of 3D short range static ordered clusters occurs far below the spin-glass freezing temperature at T ~ 4 K as it can be seen from the Li NMR spectrum.
非化学计量比体系LiNiSbO是之字形蜂窝状反铁磁体LiNiSbO的锂缺陷衍生物。通过X射线衍射、磁化率、比热和核磁共振测量研究了LiNiSbO的结构和磁性。粉末X射线衍射数据表明形成了一个新相，相对于结构上呈蜂窝状有序的LiNiSbO，该相富含Sb且锂不足。与化学计量比的对应物相比，这种结构修饰表现为磁性的急剧变化。体相静态（直流）磁化率测量表明Ni自旋（= 1）之间存在整体反铁磁相互作用（= -4 K），而动态（交流）磁化率揭示在冻结温度~ 8 K时转变为自旋玻璃态。比热（T）在低至2 K时没有λ异常，这支持了这些结果。此外，体相静态磁化率、热容量和锂核磁共振研究的结合表明磁性系统存在复杂的温度转变。我们观察到簇状自旋玻璃的发展，其中类伊辛Ni磁矩在12 K时就已表现出二维相关的缓慢短程动力学，而从锂核磁共振谱可以看出，三维短程静态有序簇的形成发生在远低于自旋玻璃冻结温度T ~ 4 K时。
