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DOE OSTI · 2519657

Surface magnetism in Fe 3 GeTe 2 van der Waals ferromagnet

Tyson, Trevor Anthony [New Jersey Institute of Technology (NJIT), Newark, NJ (United States)] (ORCID:0000000186461470)·Amarasinghe, Sandun [New Jersey Institute of Technology (NJIT), Newark, NJ (United States)]·Abeykoon, Milinda [Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)]·Lalancette, Roger [Rutgers University, Newark, NJ (United States)]·Du, Kai [Rutgers Univ., Piscataway, NJ (United States)]·Fang, Xiaochen [Rutgers Univ., Piscataway, NJ (United States)]·Cheong, Sang-Wook [Rutgers Univ., Piscataway, NJ (United States)] (ORCID:0000000199056175)·Al-Mahboob, Abdullah [Brookhaven National Laboratory (BNL), Upton, NY (United States)]·Sadowski, Jerzy T. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)] (ORCID:0000000243657796)
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Abstract

The surface magnetization of Fe 3 GeTe 2 was examined by low-energy electron microscopy (LEEM) using an off-normal incidence electron beam. We found that the 180o domain walls are of Bloch type. Temperature-dependent LEEM measurements yield a surface magnetization with a surface critical exponent β1 = 0.79±0.02. This result is consistent with surface magnetism in the 3D semi-infinite Heisenberg (β1 = 0.84±0.01) or Ising (β1 = 0.78±0.02) models, which is distinctly different from the bulk exponent (β = 0.34±0.07). Further, the measurements reveal the power of LEEM with a tilted beam to determine magnetic domain structure in quantum materials, without need for the use of spin-polarized electrons. Single crystal diffraction measurements reveal inversion symmetry-breaking weak peaks and yield space group P-6m2. This Fe site defect-derived loss of inversion symmetry enables the formation of skyrmions in this Fe 3 GeTe 2 crystal.

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Tyson, Trevor Anthony [New Jersey Institute of Technology (NJIT), Newark, NJ (United States)] (ORCID:0000000186461470), Amarasinghe, Sandun [New Jersey Institute of Technology (NJIT), Newark, NJ (United States)], Abeykoon, Milinda [Brookhaven National Laboratory (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)], Lalancette, Roger [Rutgers University, Newark, NJ (United States)], Du, Kai [Rutgers Univ., Piscataway, NJ (United States)], Fang, Xiaochen [Rutgers Univ., Piscataway, NJ (United States)], Cheong, Sang-Wook [Rutgers Univ., Piscataway, NJ (United States)] (ORCID:0000000199056175), Al-Mahboob, Abdullah [Brookhaven National Laboratory (BNL), Upton, NY (United States)], Sadowski, Jerzy T. [Brookhaven National Laboratory (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)] (ORCID:0000000243657796). 2025-02-10. Surface magnetism in Fe 3 GeTe 2 van der Waals ferromagnet. https://doi.org/10.1088/2053-1583%2Fadb43f

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