Antiferromagnetic Spin Fluctuations and Structural Transition in Cluster Mott Insulator Candidate Nb_(3)Cl_(8)Revealed by^(93)Nb-and^(35)Cl-NMR  

作　　者：Y.Z.Zhou X.Han J.Luo D.T.Wu A.F.Fang B.Shen B.J.Feng Y.G.Shi J.Yang R.Zhou 

机构地区：[1]Institute of Physics,Chinese Academy of Sciences,and Beijing National Laboratory for Condensed Matter Physics,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China [3]Center for Neutron Science and Technology,Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices,School of Physics,Sun Yat-Sen University,Guangzhou 510275,China [4]State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-Sen University,Guangzhou 510275,China [5]School of Physics and Astronomy,Beijing Normal University,Beijing 100875,China [6]Key Laboratory of Multiscale Spin Physics,Ministry of Education,Beijing Normal University,Beijing 100875,China

出　　处：《Chinese Physics Letters》2025年第3期153-166,共14页中国物理快报(英文版)

基　　金：supported by the National Key Research and Development Projects of China(Grant Nos.2022YFA1403402,2023YFA1406103,2024YFA1409200,2024YFA1611302,and 2023YFF0718400);the National Natural Science Foundation of China(Grant Nos.12374142,12304170,W2411004,and 12374197);the Beijing Natural Science Foundation(Grant No.JQ23001);the Beijing National Laboratory for Condensed Matter Physics(Grant No.2024BNLCMPKF005);the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023B151520013);supported by the Synergetic Extreme Condition User Facility(SECUF,https://cstr.cn/31123.02.SECUF)。

摘　　要：Motivated by recent studies of the cluster Mott insulator candidate compound Nb_(3)Cl_(8),this study performs^(93)Nb and^(35)Cl nuclear magnetic resonance(NMR)measurements to investigate the electron correlations.Below the structural transition temperature T_(s)∼97 K,all satellites of the^(93)Nb NMR spectra split into three distinct peaks,which suggests symmetry lowering due to the structural transition and could be attributed to the change in the Nb-Nb bond-lengths of the Nb3 clusters.The spin-lattice relaxation rate 1/T_(1)divided by the temperature T,1/T_(1)T,increases upon cooling to T_(s)for all Cl sites,whereas only the Knight shift K of Cl located at the center of the Nb3 clusters exhibits a temperature dependence similar to that observed in magnetic susceptibility.These findings collectively demonstrate the existence of strong spin correlations between the Nb atoms in Nb_(3)Cl_(8),which are closely associated with Mottness.

关 键 词：NMR) FERROMAGNETIC Transition 

分 类 号：O57[理学—粒子物理与原子核物理]