Controlling the direction of ferromagnetism and antiferromagnetism by an electric field in single-phase multiferroics will open the door to the next generation of devices for spintronics and electronics. The typical magnetoelectric coupling such as the linear magnetoelectric effect is very weak in type-I multiferroics and therefore the magnetoelectric switching is rarely achieved. Here, using first-principles simulations, we propose a magnetoelectric switching mechanism to achieve such highly desired control in orthorhombic multiferroics. One class of two-dimensional proper multiferroics (CrX₂Se₃ and MnX₂Te₃, X = Sn, Ge) and perovskite multiferroics (EuTiO₃ and BiFeO₃/LaFeO₃ superlattice) are taken as examples to show the mechanism. In the ferroelectric switching process, the proper polarization rotates its direction by 180° and keeps its magnitude almost unchanged, the ferromagnetic or antiferromagnetic vector is rotationally switched by 180° following the rotation of ferroelectric polarization. This rotational magnetoelectric switching results from in-plane structural anisotropy and magnetic anisotropy, and the process of switching is governed by cosine functions from the phenomenological Landau-type models. This study addresses the challenge of magnetoelectric switching in type-I multiferroics by proposing a general magnetoelectric switching mechanism.

通过单相多铁性中的电场控制铁磁性和反铁磁性的方向将为下一代自旋电子学和电子学设备打开大门。典型的磁电耦合（例如线性磁电效应）在I型多铁性材料中非常弱，因此很少实现磁电切换。在这里，利用第一原理模拟，我们提出了一种磁电切换机制，以在正交多铁性材料中实现如此高度期望的控制。以一类二维本征多铁性材料（Cr X ₂ Se ₃和Mn X ₂ Te ₃，X  =Sn，Ge）和钙钛矿多铁性材料（EuTiO ₃和BiFeO ₃ /LaFeO ₃超晶格）为例来说明其机理。在铁电转换过程中，原极化方向旋转180°，大小几乎不变，铁磁或反铁磁矢量随着铁电极化旋转也旋转转换180°。这种旋转磁电切换是由面内结构各向异性和磁各向异性产生的，并且切换过程由现象学朗道型模型的余弦函数控制。这项研究通过提出一种通用的磁电切换机制来解决 I 型多铁性材料中磁电切换的挑战。