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Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
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Unusual Magnetic Features in Two-Dimensional Fe5GeTe2 Induced by Structural Reconstructions
Soheil Ershadrad1, Sukanya Ghosh1, Duo Wang1
1Department of Physics and Astronomy, Uppsala University, Box-516, 75120 Uppsala, Sweden.
The Journal of Physical Chemistry Letters
|May 26, 2022
Summary
Fe5GeTe2 exhibits a novel crystal structure due to iron atom swapping in its monolayer form. This leads to complex magnetic ordering and exotic temperature-dependent magnetization, explaining experimental observations.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Materials Science
Background:
- Recent experiments on iron-germanium-telluride (Fe5GeTe2) indicated a symmetry breaking in its crystal structure.
- Understanding the atomic and magnetic structure is crucial for novel material applications.
Purpose of the Study:
- To elucidate the atomic mechanism behind the observed (√3 × √3)R30° supercell structure in monolayer Fe5GeTe2.
- To investigate the magnetic properties and their relation to the structural changes.
Main Methods:
- Density functional theory (DFT) calculations were employed to model atomic structures and energies.
- Monte Carlo simulations were used to study magnetic properties and temperature dependence.
Main Results:
- Fe atom swapping, facilitated by Fe vacancies and low diffusion barriers, stabilizes the supercell structure.
- Calculated magnetic exchange parameters reveal coexisting ferromagnetic and antiferromagnetic interactions.
- Simulations show exotic temperature-dependent magnetization and a complex noncollinear magnetic order at low temperatures.
Conclusions:
- The low-temperature crystal structure of Fe5GeTe2 arises from Fe sublattice swapping.
- This structural change explains the peculiar magnetization observed in experiments, suggesting potential for novel magnetic phenomena.
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