Seo Junho, An Eun Su, Park Taesu, Hwang Soo-Yoon, Kim Gi-Yeop, Song Kyung, Noh Woo-Suk, Kim J Y, Choi Gyu Seung, Choi Minhyuk, Oh Eunseok, Watanabe Kenji, Taniguchi Takashi, Park J -H, Jo Youn Jung, Yeom Han Woong, Choi Si-Young, Shim Ji Hoon, Kim Jun Sung
Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.
Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
Nat Commun. 2021 May 14;12(1):2844. doi: 10.1038/s41467-021-23122-y.
Discovery of two dimensional (2D) magnets, showing intrinsic ferromagnetic (FM) or antiferromagnetic (AFM) orders, has accelerated development of novel 2D spintronics, in which all the key components are made of van der Waals (vdW) materials and their heterostructures. High-performing and energy-efficient spin functionalities have been proposed, often relying on current-driven manipulation and detection of the spin states. In this regard, metallic vdW magnets are expected to have several advantages over the widely-studied insulating counterparts, but have not been much explored due to the lack of suitable materials. Here, we report tunable itinerant ferro- and antiferromagnetism in Co-doped FeGeTe utilizing the vdW interlayer coupling, extremely sensitive to the material composition. This leads to high T antiferromagnetism of T ~ 226 K in a bulk and ~210 K in 8 nm-thick nanoflakes, together with tunable magnetic anisotropy. The resulting spin configurations and orientations are sensitively controlled by doping, magnetic field, and thickness, which are effectively read out by electrical conduction. These findings manifest strong merits of metallic vdW magnets as an active component of vdW spintronic applications.
二维（2D）磁体的发现，呈现出本征铁磁（FM）或反铁磁（AFM）序，加速了新型二维自旋电子学的发展，其中所有关键组件均由范德华（vdW）材料及其异质结构制成。人们已经提出了高性能且节能的自旋功能，这通常依赖于电流驱动的自旋态操控与检测。在这方面，金属范德华磁体预计比广泛研究的绝缘磁体具有若干优势，但由于缺乏合适的材料，尚未得到充分探索。在此，我们报告了利用对材料成分极为敏感的范德华层间耦合，在Co掺杂的FeGeTe中实现可调谐的巡游铁磁性和反铁磁性。这导致了体材料中约226 K以及8纳米厚纳米片中约210 K的高温反铁磁性，同时伴有可调谐的磁各向异性。由此产生的自旋构型和取向可通过掺杂、磁场和厚度进行灵敏控制，并可通过导电有效地读出。这些发现彰显了金属范德华磁体作为范德华自旋电子学应用活性组件的强大优势。
