Muneta Iriya, Shirokura Takanori, Hai Pham Nam, Kakushima Kuniyuki, Tsutsui Kazuo, Wakabayashi Hitoshi
Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Yokohama, Japan.
Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Tokyo, Japan.
Sci Rep. 2022 Oct 13;12(1):17199. doi: 10.1038/s41598-022-22113-3.
Layered materials, such as graphene and transition metal dichalcogenides, are able to obtain new properties and functions through the modification of their crystal arrangements. In particular, ferromagnetism in polycrystalline MoS is of great interest because the corresponding nonmagnetic single crystals exhibit spontaneous spin splitting only through the formation of grain boundaries. However, no one has reported direct evidence of this unique phenomenon thus far. Herein, we demonstrate ferromagnetism modulation by an ultralow current density < 10 A/cm in 7.5-nm-thick polycrystalline MoS, in which magnetoresistance shows three patterns according to the current intensity: wide dip, nondip and narrow dip structures. Since magnetoresistance occurs because of the interaction between the current of 4d electrons in the bulk and localized 4d spins in grain boundaries, this result provides evidence of the current modulation of ferromagnetism induced by grain boundaries. Our findings pave the way for the investigation of a novel method of magnetization switching with low power consumption for magnetic random access memories.
诸如石墨烯和过渡金属二硫属化物之类的层状材料能够通过改变其晶体排列来获得新的性质和功能。特别是，多晶MoS中的铁磁性备受关注，因为相应的非磁性单晶仅通过形成晶界才会表现出自发自旋分裂。然而，迄今为止，尚无一人报道过这一独特现象的直接证据。在此，我们展示了在7.5纳米厚的多晶MoS中，通过小于10 A/cm的超低电流密度实现铁磁性调制，其中磁阻根据电流强度呈现出三种模式：宽凹陷、无凹陷和窄凹陷结构。由于磁阻是由体内4d电子电流与晶界处局域4d自旋之间的相互作用引起的，这一结果为晶界诱导的铁磁性电流调制提供了证据。我们的发现为研究用于磁性随机存取存储器的低功耗磁化切换新方法铺平了道路。
