Thermal Cycling Induced Alteration of the Stacking Order and Spin-Flip in the Room Temperature van der Waals Magnet Fe5GeTe2

December 27, 2023
Crystals structure of Fe5GeTe2 with ABC-stacking order
Crystals structure of Fe5GeTe2 with ABC-stacking order (left) and AA-stacking order (upper right). Neutron diffraction data: Temperature dependence (lower right panels) of (1 0 4) peak shows the magnetic order at TC0 and structural transition at Ts during the first cool process.

Scientific Achievement

Single crystal neutron and X-ray diffraction study reveal intriguing thermal cycling effect on the structural and magnetic properties in van der Waals magnet Fe5GeTe2.   

Significance and Impact

This work shows that the spin moment direction is directly controlled by the stacking order of the lattice in quenched Fe5GeTe2 highlighting the profound effect of different stacking order of lattice on the magnetism in this quasi-two-dimensional magnet.  

Research Details

  • Fe5GeTe2 single crystals were synthesised via the chemical vapor transfer technique and quenched from 750° C to room temperature.
  • Magnetization reveals thermal history.
  • Magnetic order was determined by neutron diffraction.
  • The structural transition was characterized by X-ray diffraction.

“Thermal cycling induced alteration of the stacking order and spin-flip in the room temperature van der Waals magnet Fe5GeTe2“ 
Xiang Chen, Wei Tian, Yu He, Hongrui Zhang, Tyler L. Werner, Saul Lapidus, Jacob P. C. Ruff, Ramamoorthy Ramesh, and Robert J. Birgeneau, 
Physical Review Materials, 7, 044411 (2023). DOI: