Pang Kaijuan, Xu Xiaodong, Ku Ruiqi, Wei Yadong, Ying Tao, Li Weiqi, Yang Jianqun, Li Xingji, Jiang Yongyuan
School of Physics, Harbin Institute of Technology, Harbin150001, China.
School of Material Science and Engineering, Harbin Institute of Technology, Harbin150001, China.
ACS Appl Mater Interfaces. 2023 Feb 12. doi: 10.1021/acsami.2c18812.
The breaking of the out-of-plane symmetry makes a two-dimensional (2D) Janus monolayer a new platform to explore the coupling between ferroelectricity and ferromagnetism. Using density functional theory in combination with Monte Carlo simulations, we report a novel phase-switchable 2D multiferroic material VInSe with large intrinsic out-of-plane spontaneous electric polarization and a high Curie temperature (). The structural transition energy barrier between the two phases is determined to be 0.4 eV, indicating the switchability of the electric polarizations and the potential ferroelectricity. Carrier doping can boost the Curie temperature above room temperature, attributing to the enhanced magnetic exchange interaction. A transition from the ferromagnetic (FM) state to the antiferromagnetic (AFM) state can be induced by carrier doping in octahedra-VInSe, while FM coupling is well-preserved in tetrahedron-VInSe, which can be regulated to be either an XY or Ising magnet at an appropriate carrier concentration. These findings not only enrich the family of high low-dimensional monolayers but also offer a new direction for the design and multifunctional application of multiferroic materials.
面外对称性的打破使二维（2D）Janus单层成为探索铁电性与铁磁性之间耦合的新平台。结合密度泛函理论和蒙特卡罗模拟，我们报道了一种新型的具有大的本征面外自发极化和高居里温度（）的二维多铁性材料VInSe。确定了两相之间的结构转变能垒为0.4 eV，这表明了电极化的可切换性以及潜在的铁电性。载流子掺杂可将居里温度提高到室温以上，这归因于增强的磁交换相互作用。在八面体-VInSe中，载流子掺杂可诱导从铁磁（FM）态到反铁磁（AFM）态的转变，而在四面体-VInSe中FM耦合得到很好的保留，在适当的载流子浓度下，四面体-VInSe可被调控为XY磁体或伊辛磁体。这些发现不仅丰富了高低维单层材料家族，也为多铁性材料的设计和多功能应用提供了新方向。
