Theoretical design of two dimensional magnetoelectrics

Achieving magnetoelectric two-dimensional (2D) materials should enable numerous functionalities in nanoscale devices. Until now, however, predicted 2D magnetoelectric materials are very few and with coexisting yet only loosely coupled (type-I) ferroelectricity and magnetism [1]. Based on physical analysis and by using density functional theory calculations, a type-II multiferroic MXene Hf₂VC₂F₂ monolayer is predicted. For multiferroic MXene Hf₂VC₂F₂ monolayer, its ferroelectricity originates directly from its magnetism [2]. The noncollinear 120^o Y-type spin order generates a polarization perpendicular to the spin helical plane. Remarkably, the multiferroic transition is estimated to occur above room temperature. Our investigation should open the door to a new branch of 2D materials in the pursuit of intrinsically strong magnetoelectricity.

[1] Y.H. Zhao, L.F. Lin, Q.H. Zhou, Y.H. Li, S.J. Yuan, Q. Chen, S. Dong, J.L. Wang, Nano Letters 18, 2943 (2018).
[2] J.-J. Zhang, L.F. Lin, Y. Zhang, M.H. Wu, B. Yakobson, S. Dong, J. Am. Chem. Soc. 140, 9768 (2018).