Ticknor John O, Umegaki Izumi, McFadden Ryan M L, Chatzichristos Aris, Fujimoto Derek, Karner Victoria L, Kiefl Robert F, Kobayashi Shintaro, Levy C D Philip, Li Ruohong, Morris Gerald D, Pearson Matthew R, Yoshimura Kazuyoshi, Sugiyama Jun, MacFarlane W Andrew
Department of Chemistry, University of British Columbia Vancouver BC V6T 1Z1 Canada
Stewart Blusson Quantum Matter Institute, University of British Columbia Vancouver BC V6T 1Z4 Canada.
RSC Adv. 2020 Feb 26;10(14):8190-8197. doi: 10.1039/c9ra07065f. eCollection 2020 Feb 24.
We have studied a mosaic of 1T-CrSe single crystals using β-detected nuclear magnetic resonance of Li from 4 to 300 K. We identify two broad resonances that show no evidence of quadrupolar splitting, indicating two magnetically distinct environments for the implanted ion. We observe stretched exponential spin lattice relaxation and a corresponding rate (1/ ) that increases monotonically above 200 K, consistent with the onset of ionic diffusion. A pronounced maximum in 1/ is observed at the low temperature magnetic transition near 20 K. Between these limits, 1/ exhibits a broad minimum with an anomalous absence of strong features in the vicinity of structural and magnetic transitions between 150 and 200 K. Together, the results suggest Li site occupation within the van der Waals gap between CrSe trilayers. Possible origins of the two environments are discussed.
我们利用锂的β探测核磁共振技术，在4至300K的温度范围内研究了1T-CrSe单晶的镶嵌体。我们识别出两个宽共振峰，未观察到四极分裂的迹象，这表明注入离子存在两种磁性不同的环境。我们观察到拉伸指数自旋晶格弛豫以及相应的速率(1/T₁)，其在200K以上单调增加，这与离子扩散的开始相一致。在接近20K的低温磁转变处，观察到1/T₁出现明显的最大值。在这些极限之间，1/T₁呈现出一个宽的最小值，在150至200K之间的结构和磁转变附近异常地没有强特征。综合来看，结果表明锂占据了CrSe三层之间范德华间隙中的位置。文中讨论了这两种环境的可能来源。
