Huan Yahuan, Luo Tiantian, Han Xiaocang, Ge Jun, Cui Fangfang, Zhu Lijie, Hu Jingyi, Zheng Feipeng, Zhao Xiaoxu, Wang Lili, Wang Jian, Zhang Yanfeng
School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China.
Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, 510632, P. R. China.
Adv Mater. 2023 Jan;35(1):e2207276. doi: 10.1002/adma.202207276. Epub 2022 Nov 21.
Exploring new-type 2D magnetic materials with high magnetic transition temperature and robust air stability has attracted wide attention for developing innovative spintronic devices. Recently, intercalation of native metal atoms into the van der Waals gaps of 2D layered transition metal dichalcogenides (TMDs) has been developed to form 2D non-layered magnetic TMDs, while only succeeded in limited systems (e.g., Cr S , Cr Te ). Herein, composition-controllable syntheses of 2D non-layered iron selenide nanosheets (25% Fe-intercalated triclinic Fe Se and 50% Fe-intercalated monoclinic Fe Se ) are firstly reported, via a robust chemical vapor deposition strategy. Specifically, the 2D Fe Se exhibits intrinsic room-temperature ferromagnetic property, which is explained by the change of electron spin states from layered 1T'-FeSe to non-layered Fe-intercalated Fe Se based on density functional theory calculations. In contrast, the ultrathin Fe Se presents novel metallic features comparable with that of metallic TMDs. This work hereby sheds light on the composition-controllable synthesis and fundamental property exploration of 2D self-intercalation induced novel TMDs compounds, by propelling their application explorations in nanoelectronics and spintronics-related fields.
探索具有高磁转变温度和强空气稳定性的新型二维磁性材料，对于开发创新的自旋电子器件具有重要意义，已引起广泛关注。最近，人们通过将天然金属原子插入二维层状过渡金属二硫属化物（TMDs）的范德华间隙中，成功制备出二维非层状磁性TMDs，但仅在有限的体系中取得成功（如CrS、CrTe）。在此，我们首次报道了通过一种稳健的化学气相沉积策略，可控合成二维非层状硒化铁纳米片（25%铁插入的三斜晶系FeSe和50%铁插入的单斜晶系FeSe）。具体而言，二维FeSe具有本征室温铁磁特性，基于密度泛函理论计算，这可由电子自旋态从层状1T'-FeSe转变为非层状铁插入的FeSe来解释。相比之下，超薄FeSe呈现出与金属TMDs相当的新颖金属特性。本工作通过推动二维自插入诱导新型TMDs化合物在纳米电子学和自旋电子学相关领域的应用探索，为其可控合成及基本性质研究提供了新的思路。
