中国物理B ›› 2026, Vol. 35 ›› Issue (5): 57601-057601.doi: 10.1088/1674-1056/ae194e
Ubaid Raza1,2, Zhijie Ma(马之杰)1, Fangwei Wang(王芳卫)1,2, Youguo Shi(石友国)1, Lunhua He(何伦华)1,2, and Liqin Yan(闫丽琴)1,2,†
Ubaid Raza1,2, Zhijie Ma(马之杰)1, Fangwei Wang(王芳卫)1,2, Youguo Shi(石友国)1, Lunhua He(何伦华)1,2, and Liqin Yan(闫丽琴)1,2,†
摘要: This study investigates the microscopic spin dynamics and anisotropic magnetic behavior in van der Waals kagome magnet Nb$_3$Cl$_8$ by employing electron spin resonance (ESR) spectroscopy on both powder and single-crystal samples over the temperature range of 5 K-300 K. The effective $g$, peak to peak linewidths ($\Delta H_{\rm pp}$), and double integrated intensities ($I$) were extracted from the ESR spectra to analyze the temperature-dependent evolution of spin-orbit coupling and spin-spin interactions. The formation of singlet ground state in single crystal Nb$_3$Cl$_8$ at $T^*\sim100$ K is observed, evidenced by the maximum $\Delta H_{\rm pp}$ and $g$ at $T^*$, along with the decrease in intensity $I$, which is consistent to the reported non-magnetic transition in the single-crystal Nb$_3$Cl$_8$. Moreover, the spectral difference between $H\parallel c$ and $H\bot c$ configurations imply subtle magnetic anisotropy in single crystal Nb$_3$Cl$_8$. However, there is no non-magnetic transition was observed in powder Nb$_3$Cl$_8$ since the parameters of $\Delta H_{\rm pp}$ and $I$ keep stable at $T^*$. It might be attributed to the grain averaging and random orientation effects. Our study provides valuable insights into the magnetic interplay in Nb$_3$Cl$_8$ and prove the potential of ESR spectroscopy as a powerful tool for probing the intrinsic magnetism.
中图分类号: (Electron paramagnetic resonance and relaxation)