Near-Room-Temperature Field-Controllable Exchange Bias in 2D van der Waals Ferromagnet Fe3GaTe2
arxiv(2024)
Abstract
Exchange bias (EB) is a cornerstone of modern magnetic memory and sensing
technologies. Its extension to the realm of two-dimensional (2D) van der Waals
(vdW) magnets holds promise for revolutionary advancements in miniaturized and
efficient atomic spintronic devices. However, the blocking temperature of EB in
2D vdW magnets is currently well below room temperature 130 K. This study
reports a robust EB phenomenon in Fe3GaTe2 thin-layer devices, which
significantly increases the blocking temperature to a near-room-temperature
record of 280 K. Both the bias direction and magnitude can be isothermally
tuned by adjusting the field sweep range, in striking contrast to the
conventional EB in ferromagnetic/antiferromagnetic (FM/AFM) bilayers. We
propose an exchange spring model in which crystal defects with higher
coercivity act as the pivotal pinning source for the observed EB phenomenon,
deviating from the conventional FM/AFM interface mechanism. Cumulative growth
of minor loops and multiple magnetization reversal paths are observed in field
cycles below the saturation field, consistent with the hard FM defects behavior
of our exchange spring model. These findings provide insights into the complex
magnetic order in 2D ferromagnets and open new avenues for developing practical
ultrathin vdW spintronic devices with EB-like properties at room temperature.
MoreTranslated text
AI Read Science
Must-Reading Tree
Example
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined