Valence mediated tunable magnetism and electronic properties by ferroelectric polarization switching in 2D FeI2/In2Se3 van der Waals heterostructures
Valence mediated tunable magnetism and electronic properties by ferroelectric polarization switching in 2D FeI2/In2Se3 van der Waals heterostructures
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2D FeI2/In2Se3 范德华异质结构中铁电极化介导的价介导可调磁性和电子特性
DOI：
10.1039/c9nr01510h
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发表时间：
2019
期刊：
影响因子：
6.7
通讯作者：
Wang Yuanxu
中科院分区：
文献类型：
--
作者：
Sun Wei;Wang Wenxuan;Chen Dong;Cheng Zhenxiang;Wang Yuanxu
探索具有铁磁和铁电性质的二维（2D）材料在科学上是有趣的，并且对于纳米器件中的许多功能具有重要的技术意义。在这项工作中，我们已经证明了一个强大的磁电耦合，出现在二维FeI 2/In 2 Se 3货车德瓦尔斯异质结构。FeI 2层通过反转铁电极化方向而经历从铁磁到反铁磁的转变。第一性原理计算预测了一种新的磁电耦合机制，它与多铁性材料中的Dzyaloshinskiii-Moriya（DM）效应完全不同。由于界面处的极化不连续性，Fe离子的价态在两个不同的极化方向上在+2和+3之间变化，导致直接交换和I离子介导的超交换之间的磁相互作用发生变化。此外，金属二维电子气（2DEG）从FeI 2的表面转移到In 2Se 3时，极化反转，这导致的自旋极化的异质结构从93%到0%的变化。我们的工作是第一次实现了在全二维货车德瓦耳斯异质结构中通过电场来操纵磁性。
Exploring two-dimensional (2D) materials with both ferromagnetic and ferroelectric properties is scientifically interesting and of great technical importance to numerous functionalities in nanoscale devices. In this work, we have demonstrated a strong magnetoelectric coupling that appeared in the 2D FeI2/In2Se3 van der Waals heterostructure. FeI2 layers undergo a transition from ferromagnetic to antiferromagnetic by reversing the direction of ferroelectric polarization. First-principles calculation predicts a new magnetoelectronic coupling mechanism which is completely different from the Dzyaloshinskii–Moriya (DM) effect in multiferroic materials. Because of the polarization discontinuity at the interface, the valence states of Fe ions change between +2 and +3 for two different polarization directions, leading to the magnetic interaction variation between the direct exchange and I ion mediated superexchange. Moreover, metallic 2D electron gas (2DEG) transfers from the surface of FeI2 to In2Se3 when the polarization reverses, which induces the spin polarization of the heterostructure varying from 93% to 0%. Our work is the first realization of manipulation magnetism by an electric field in full 2D van der Waals heterostructures.