The extracted Kerr rotations as functions of the temperature for Fe3GeTe2(FGT) and FePS3 (FPS)/FGT, which shows the Significant enhancements of Curie temperature TC.The left figure shows Typical MOKE signal for an FGT flake and an FPS/FGT heterostructure measured at 80 K, which indicates the improvement of coercive Hc. Figure in the upper right is theschematic of the MOKE measurement of FPS/FGT heterostructure.
(Advanced Materials 2002032, 2020)
Background
The recent discovery of intrinsic ferromagnetism in atomic thin two-dimensional (2D) magnets opens a door to investigate novel physics and devices for spintronic applications. However, the Curie temperature TC of most of the obtained van der Waals (vdW) ferromagnets is far below room temperature. Therefore, it is crucial to enhance the magnetic properties of the observed ferromagnets (FMs) to meet the requirements of industrial applications, before new room-temperature 2D FMs would be found. In our work, new vdW ferromagnet/antiferromagnet heterostructures, composed of ultrathin ferromagnetic Fe3GeTe2 (FGT) and antiferromagnetic FePS3(FPS), were constructed and explored. Significant enhancements of Curie temperature TC, coercive Hc were obtained without any external energy.
What did we discover?
We fabricated the heterostructures of FPS/FGT and FPS/FGT/FPS and measured the magnetic properties of them. The results show that, through the coupling of FGT with FPS, the TC was improved by more than 30 K and the coercive field (HC) was increased by ~100%. We successfully promote the magnetic properties of FGT without any external energy.
Why is this important?
Most of the observed 2D FMs only have long-range order at low temperatures, it is therefore crucial to increase the Curie temperature (TC) of the FMs to meet the requirements of industrial applications, before new room-temperature 2D FMs would be found. Our work reveals that antiferromagnet/ferromagnet coupling is a promising way to engineer the magnetic properties of itinerant 2D ferromagnet,which paves the way for applications in advanced magnetic spintronic and memory devices.
Why did they need WHMFC?
All the measurements in this work were performed in WHMFC. The hysteresis loop curves of FGT and FPS/FGT were performed by using the lab-made Magneto-optical Kerr effect setup and the magnetic properties of FPS were measured by using the high magnetic field magnetism measurement setups.
Who did the research?
Luman Zhang,†‡Xinyu Huang,§‡Hongwei Dai,†Mingshan Wang,†Hui Cheng,†Lei Tong,§Zheng Li,§Xiaotao Han,†Xia Wang,#Lei Ye,§*Junbo Han†*
† Wuhan National High Magnetic Field Center and Department of Physics,Huazhong University of Science and Technology,Wuhan 430074, P. R. China
§ School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology,Wuhan 430074, P. R. China
# School of Mathematics and Physics,Wenhua College,Wuhan 430074, P. R. China
https://www.onlinelibrary.wiley.com/doi/full/10.1002/adma.202002032
