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 (TC) 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 Cr2Ge2Te6 (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 TC 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.
@article{arxiv.2312.17554,
title = {Spin-glass states generated in a van der Waals magnet by alkali-ion intercalation},
author = {S. Khan and E. S. Y. Aw and L. A. V. Nagle-Cocco and A. Sud and S. Ghosh and M. K. B. Subhan and Z. Xue and C. Freeman and D. Sagkovits and A. Gutierrez-Llorente and I. Verzhbitskiy and D. M. Arroo and C. W. Zollitsch and G. Eda and E. J. G. Santos and S. E. Dutton and S. T. Bramwell and C. A. Howard and H. Kurebayashi},
journal= {arXiv preprint arXiv:2312.17554},
year = {2024}
}