文献类型：期刊文献

英文题名：Room-temperature intrinsic ferromagnetism of two-dimensional Na2Cl crystals originated by s- and p-orbitals

作者：Zhao, Yimin[1]; Li, Yunzhang[2]; Chen, Liang[3,4]; Zhang, Quan[1]; Liu, Xing[2]; Yang, Yizhou[5]; Yi, Ruobing[1,4]; Zhang, Lihao[1]; He, Zhenglin[2]; Qiu, Yinwei[4]; Nie, Dexi[1]; Tian, Fanghua[1]; Wang, Zhe[1]; Yang, Zhiwei[1]; Zhang, Lei[1]; Shi, Guosheng[2]; Zhang, Shengli[1]; Fang, Haiping[5]

机构：[1] MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'An, 710049, China; [2] Shanghai Applied Radiation Institute, Shanghai University, Shanghai, 200444, China; [3] School of Physical Science and Technology, Ningbo University, Ningbo, 315211, China; [4] Department of Optical Engineering, Zhejiang Prov Key Lab Carbon Cycling Forest Ecosy, Zhejiang Prov Key Lab of Chemical Utilization of Forestry Biomass, Zhejiang A&F University, Lin'An, 311300, China; [5] School of Science, East China University of Science and Technology, Shanghai, 200237, China

年份：2024

外文期刊名：arXiv

收录：EI(收录号：20240039651)

语种：英文

外文关键词：Chlorine - Crystal atomic structure - Electron microscopes - Electron microscopy - Electronic structure - Ferromagnetic materials - Graphene - Magnetic moments - Room temperature - Sodium - SQUIDs - Thermoelectric equipment

摘要：Ferromagnetism, as one of the most valuable properties of materials, has attracted sustained and widespread interest in basic and applied research from ancient compasses to modern electronic devices1-7. Traditionally, intrinsic ferromagnetism has been attributed to the permanent magnetic moment induced by partially filled d- or f-orbitals8. However, the development of ferromagnetic materials has been limited by this electronic structure convention. Thus, the identification of additional materials that are not constrained by this conventional rule but also exhibit intrinsic ferromagnetism is highly expected and may impact all the fields based on ferromagnetism. Here, we report the direct observation of room-temperature intrinsic ferromagnetism in two-dimensional (2D) Na2Cl crystals, in which there are only partially filled s- and p-orbitals rather than d- or f-orbitals, using the superconducting quantum interference device (SQUID) and magnetic force microscope (MFM). These Na2Cl crystals formed in reduced graphene oxide (rGO) membranes have an unconventional stoichiometric structure leading to unique electron and spin distributions. And the structure of these 2D Na2Cl crystals, including the Na and Cl sites, is characterized in situ for the first time and directly observed by cryo-electron microscopy (cryo-EM) based on the observed difference in contrast between Na stacked with Cl and single Na. These findings break the conventional rule of intrinsic ferromagnetism and provide new insights into the design of novel magnetic and electronic devices and transistors with a size down to the atomic scale. Copyright ? 2024, The Authors. All rights reserved.