Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Spin-glass states, a fascinating phenomenon in magnetic materials, have been successfully generated in a van der Waals (vdW) magnet through alkali-ion intercalation. This groundbreaking study, published in Advanced Materials on July 22, 2024, opens new avenues in magnetic materials research and potential applications in advanced technologies.

 

Researchers from University College London, led by Dr. Safe Khan, and international collaborators, including Dr. Aakanksha Sud from FRIS, discovered this novel way to manipulate the magnetic properties of vdW materials. By intercalating sodium (Na) atoms into the vdW material Cr₂Ge₂Te₆ (CGT), they enhanced the Curie temperature (TC) from 66 K to 240 K and altered the magnetic easy-hard axis direction. This process created a system where magnetic frustration leads to the coexistence of spin-glass states and ferromagnetic order, showcasing a new method for tuning magnetic properties in 2D materials.

 

Dynamic magnetic susceptibility measurements confirmed the formation of magnetic clusters with slow dynamics and a distribution of relaxation times, opening new possibilities for understanding complex magnetic behaviours and enhancing magnetic material performance.

 

The authors commented, "Our research highlights the potential of intercalation as a unique method to induce magnetic frustration and generate spin-glass states in simple vdW crystals. This could lead to new functionalities in magnetic materials and advanced technological applications."

 

This research provides valuable insights into the fundamental properties of spin-glass states in vdW materials, with potential implications for advanced magnetic applications and theoretical models.

This discovery was published in Advanced Materials on July 22, 2024.
 

 

Figure: (a) The image represents the process of sodium (Na) atom intercalation into the vdW gaps of pristine Cr₂Ge₂Te₆ (CGT), generating spin-glass states that coexist with ferromagnetic order, enhancing the Curie temperature (TC) and altering the magnetic axis direction   (b) Shift in peak position of magnetic susceptibility (χ') for a frequency window of Hz–kHz indicating slow dynamics in the system and emerging spin-glass state.

Publication Details
Title: Spin-Glass States Generated in a van der Waals Magnet by Alkali-Ion Intercalation
Authors: Safe Khan, Eva S. Y. Aw, Liam A. V. Nagle-Cocco, Aakanksha Sud, Sukanya Ghosh, Mohammed K. B. Subhan, Zekun Xue, Charlie Freeman, Dimitrios Sagkovits, Araceli Gutiérrez-Llorente, Ivan Verzhbitskiy, Daan M. Arroo, Christoph W. Zollitsch, Goki Eda, Elton J. G. Santos, Sian E. Dutton, Steven T. Bramwell, Chris A. Howard, Hidekazu Kurebayashi
Journal: Advanced Materials
DOI: 10.1002/adma.202400270
URL: https://doi.org/10.1002/adma.202400270