Spin-glass states generated in a van der Waals magnet by alkali-ion intercalation

S. Khan; E. S. Y. Aw; L. A. V. Nagle-Cocco; A. Sud; S. Ghosh; M. K. B. Subhan; Z. Xue; C. Freeman; D. Sagkovits; A. Gutierrez-Llorente; I. Verzhbitskiy; D. M. Arroo; C. W. Zollitsch; G. Eda; E. J. G. Santos; S. E. Dutton; S. T. Bramwell; C. A. Howard; H. Kurebayashi

arXiv · 2312.17554

Spin-glass states generated in a van der Waals magnet by alkali-ion intercalation

S. Khan·E. S. Y. Aw·L. A. V. Nagle-Cocco·A. Sud·S. Ghosh·M. K. B. Subhan·Z. Xue·C. Freeman·D. Sagkovits·A. Gutierrez-Llorente·I. Verzhbitskiy·D. M. Arroo·C. W. Zollitsch·G. Eda·E. J. G. Santos·S. E. Dutton·S. T. Bramwell·C. A. Howard·H. Kurebayashi

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Abstract

Tuning magnetic properties in layered van der Waals (vdW) materials has captured a significant attention due to the efficient control of ground-states by heterostructuring and external stimuli. Electron doping by electrostatic gating, interfacial charge transfer and intercalation is particularly effective in manipulating the exchange and spin-orbit properties, resulting in a control of Curie temperature ($T_{\text{C}}$) and magnetic anisotropy. Here, we discover an uncharted role of intercalation to generate magnetic frustration. As a model study, we intercalate Na atoms into the vdW gaps of pristine Cr$_2$Ge$_2$Te$_6$ (CGT) where generated magnetic frustration leads to emerging spin-glass states coexisting with a ferromagnetic order. A series of dynamic magnetic susceptibility measurements/analysis confirms the formation of magnetic clusters representing slow dynamics with a distribution of relaxation times. The intercalation also modifies other macroscopic physical parameters including the significant enhancement of $T_{\text{C}}$ from 66\,K to 240\,K and the switching of magnetic easy-hard axis direction. Our study identifies intercalation as a unique route to generate emerging frustrated spin states in simple vdW crystals.

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S. Khan, E. S. Y. Aw, L. A. V. Nagle-Cocco, A. Sud, S. Ghosh, M. K. B. Subhan, Z. Xue, C. Freeman, D. Sagkovits, A. Gutierrez-Llorente, I. Verzhbitskiy, D. M. Arroo, C. W. Zollitsch, G. Eda, E. J. G. Santos, S. E. Dutton, S. T. Bramwell, C. A. Howard, H. Kurebayashi. 2023-12-29. Spin-glass states generated in a van der Waals magnet by alkali-ion intercalation. https://arxiv.org/abs/2312.17554

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