Influence of magnetism of van der Waals magnet caused by the transfer process.

Wei-Hsiang Wang^1*, Chia-Nung Kuo^2,3, Yi-Ying Lu¹, Chin-Shan Lue^2,4,3, Chien-Cheng Kuo¹

¹Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
²Physics, National Cheng Kung University, Tainan, Taiwan
³Taiwan Consortium of Emergent Crystalline Materials, National Science and Technology Council, Taipei, Taiwan
⁴Program on Key Materials, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan, Taiwan

* Presenter:Wei-Hsiang Wang, email:a29782860@gmail.com

Magnetic van der Waals (vdW) materials have emerged as promising candidates for spintronics applications and have attracted intensive studies for control and design specific magnetic properties through interfacial engineering via stacking heterostructure by transfer technique [1,2]. However, somewhat inevitable bubbles and wrinkles would be induced between different materials during the transfer process, affecting the physics properties of 2D vdW materials [3].

In this study, we present that the magnetic properties of 2D vdW magnets are sensitive to the transfer process. The high Curie temperature (T_C~478 K) 2D vdW magnet (Fe_1-XNi_X)_5-δGeTe₂ (Ni-F5GT) [4] was transferred on SiO₂/Si substrate; the bubbles and wrinkles between Ni-F5GT and substrate emerged after the transfer process. Unexpected local antiferromagnetic coupling-like loops, ferromagnetic coupling-like loops, inverted loops, and two individual magnetization layers in Ni-F5GT thin films induced by the transfer process are observed using magneto-optic Kerr effect (MOKE) microscopy at room temperature. Our results are of considerable help in understanding foundational magnetic properties of the stacking heterostructure for spintronics applications.

[1]X. Bi et al., Adv. Phys. Res. 2, 2200106 (2023).
[2]S. Bhattacharyya et al., Adv. Mater. 33, 2007795 (2021).
[3]Y. Qi et al., Adv. Mater. 35, 2205714 (2022).
[4]X. Chen et al., Phys. Rev. Lett. 128, 217203 (2022).

Keywords: 2D vdW magnets, magneto-optic Kerr effect microscopy