Vasilchikova Tatyana, Vasiliev Alexander, Evstigneeva Maria, Nalbandyan Vladimir, Lee Ji-Sun, Koo Hyun-Joo, Whangbo Myung-Hwan
Department of Low Temperature Physics and Superconductivity, Lomonosov Moscow State University, Moscow 119991, Russia.
Quantum Functional Materials Laboratory, National University of Science and Technology "MISiS", Moscow 119049, Russia.
Materials (Basel). 2022 Mar 31;15(7):2563. doi: 10.3390/ma15072563.
The static and dynamic magnetic properties and the specific heat of KNiTeO and LiNiTeO were examined and it was found that they undergo a long-range ordering at = 22.8 and 24.4 K, respectively, but exhibit a strong short-range order. At high temperature, the magnetic susceptibilities of KNiTeO and LiNiTeO are described by a Curie-Weiss law, with Curie-Weiss temperatures Θ of approximately -13 and -20 K, respectively, leading to the effective magnetic moment of about 4.46 ± 0.01 per formula unit, as expected for Ni ( = 1) ions. In the paramagnetic region, the ESR spectra of KNiTeO and LiNiTeO show a single Lorentzian-shaped line characterized by the isotropic effective -factor, = 2.19 ± 0.01. The energy-mapping analysis shows that the honeycomb layers of ANiTeO (A = K, Li) and LiNiSbO adopt a zigzag order, in which zigzag ferromagnetic chains are antiferromagnetically coupled, because the third nearest-neighbor spin exchanges are strongly antiferromagnetic while the first nearest-neighbor spin exchanges are strongly ferromagnetic, and that adjacent zigzag-ordered honeycomb layers prefer to be ferromagnetically coupled. The short-range order of the zigzag-ordered honeycomb lattices of KNiTeO and LiNiTeO is equivalent to that of an antiferromagnetic uniform chain, and is related to the short-range order of the ferromagnetic chains along the direction perpendicular to the chains.
对KNiTeO和LiNiTeO的静态和动态磁性质以及比热进行了研究，发现它们分别在22.8 K和24.4 K时发生长程有序，但表现出强烈的短程有序。在高温下，KNiTeO和LiNiTeO的磁化率由居里 - 外斯定律描述，居里 - 外斯温度Θ分别约为 - 13 K和 - 20 K，导致每个化学式单位的有效磁矩约为4.46±0.01，这与Ni（S = 1）离子的预期相符。在顺磁区，KNiTeO和LiNiTeO的电子自旋共振光谱显示出一条单一的洛伦兹线形线，其特征为各向同性的有效g因子，g = 2.19±0.01。能量映射分析表明，ANiTeO（A = K，Li）和LiNiSbO的蜂窝层采用锯齿状有序排列，其中锯齿状铁磁链是反铁磁耦合的，因为第三近邻自旋交换是强反铁磁的，而第一近邻自旋交换是强铁磁的，并且相邻的锯齿状有序蜂窝层倾向于铁磁耦合。KNiTeO和LiNiTeO的锯齿状有序蜂窝晶格的短程有序与反铁磁均匀链的短程有序相当，并且与沿垂直于链的方向的铁磁链的短程有序有关。
