Intriguing magnetoelectric effect in two-dimensional ferromagnetic/perovskite oxide ferroelectric heterostructure

Ping Li,Xue-Song Zhou,Zhi-Xin Guo

doi:10.1038/s41524-022-00706-w

Ping Li, Xue-Song Zhou + Show 1 more

Open Access

https://doi.org/10.1038/s41524-022-00706-w

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Abstract

Two-dimensional (2D) magnets have broad application prospects in the spintronics, but how to effectively control them with a small electric field is still an issue. Here we propose that 2D magnets can be efficiently controlled in a multiferroic heterostructure composed of 2D magnetic material and perovskite oxide ferroelectric (POF) whose dielectric polarization is easily flipped under a small electric field. We illustrate the feasibility of such strategy in the bilayer CrI3/BiFeO3(001) heterostructure by using the first-principles calculations. Different from the traditional POF multiferroic heterostructures which have strong interface interactions, we find that the interface interaction between CrI3 and BiFeO3(001) is van der Waals type. Whereas, the heterostructure has particular strong magnetoelectric coupling where the bilayer CrI3 can be efficiently switched between ferromagnetic and antiferromagnetic types by the polarized states P↑ and P↓ of BiFeO3(001). We also discover the competing effect between electron doping and the additional electric field on the interlayer exchange coupling interaction of CrI3, which is responsible to the magnetic phase transition. Our results provide a avenue for the tuning of 2D magnets with a small electric field.

Highlights

IntroductionIn the past two decades, the multiferroic heterostructure composed of traditional magnetic material (such as iron, cobalt, and their alloys) and perovskite oxide ferroelectric (POF) has been widely studied[1,2], due to its great potential in realizing large magnetoelectric coupling at room temperature
In the past two decades, the multiferroic heterostructure composed of traditional magnetic material and perovskite oxide ferroelectric (POF) has been widely studied[1,2], due to its great potential in realizing large magnetoelectric coupling at room temperature
By means of density functional theory (DFT) calculations (Methods are shown in Supplementary Materials), we propose a strategy for a small electric field controlling of magnetic phase transition (MPT) in the 2D magnets, i.e., 2DFM/POF heterostructures

Summary

Introduction

In the past two decades, the multiferroic heterostructure composed of traditional magnetic material (such as iron, cobalt, and their alloys) and perovskite oxide ferroelectric (POF) has been widely studied[1,2], due to its great potential in realizing large magnetoelectric coupling at room temperature. The large number of dangling bonds at the interface induces significant orbital hybridizations and even the ion migration between the magnetic material and the ferroelectric oxide (strong interface interaction)[3,4]. Such strong interface interaction usually leads to the irreversible destruction of the interface magnetic structure, and reduces the cycle life of the spintronic devices[5–9]. Constructing heterostructures of 2DFE and 2DFM potentially provides a generally applicable route to create 2D multiferroics and magnetoelectronic couplings Such heterostructure is expected to have vdW interface interaction due to the lack of dangling bonds, which is particular suitable for the infinite cycle life spintronic devices. A fundamental question is whether the vdW interlayer can induce the strong magnetoelectric coupling

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