Giant nonvolatile manipulation of magnetoresistance in magnetic tunnel junctions by electric fields via magnetoelectric coupling

Aitian Chen,Tom Wu,Bin Fang,Qiang Zhang,Xiufeng Han,Hao Wu,Haoliang Huang,Peisen Li,Jianwang Cai,Yuelei Zhao,Zhongming Zeng,Xi-Xiang Zhang,Yalin Lu,Yan Wen,Yuansi Chang,Yonggang Zhao

doi:10.1038/s41467-018-08061-5

Abstract

Electrically switchable magnetization is considered a milestone in the development of ultralow power spintronic devices, and it has been a long sought-after goal for electric-field control of magnetoresistance in magnetic tunnel junctions with ultralow power consumption. Here, through integrating spintronics and multiferroics, we investigate MgO-based magnetic tunnel junctions on ferroelectric substrate with a high tunnel magnetoresistance ratio of 235%. A giant, reversible and nonvolatile electric-field manipulation of magnetoresistance to about 55% is realized at room temperature without the assistance of a magnetic field. Through strain-mediated magnetoelectric coupling, the electric field modifies the magnetic anisotropy of the free layer leading to its magnetization rotation so that the relative magnetization configuration of the magnetic tunnel junction can be efficiently modulated. Our findings offer significant fundamental insight into information storage using electric writing and magnetic reading and represent a crucial step towards low-power spintronic devices.

Highlights

Switchable magnetization is considered a milestone in the development of ultralow power spintronic devices, and it has been a long sought-after goal for electric-field control of magnetoresistance in magnetic tunnel junctions with ultralow power consumption
A scheme of magnetic tunnel junction (MTJ) stacks grown on FE substrate was proposed theoretically[11,28,29], which relied on the recent progress in the room temperature electric-field control of magnetism in FM/FE multiferroic heterostructures[21,30,31,32,33,34,35,36,37,38,39,40]
We imaged the cross-sections of the devices used in this work using high-resolution transmission electron microscopy (HRTEM) (Supplementary Fig. 1), which confirmed experimentally that the MTJs had the designed structure

Summary

Introduction

Switchable magnetization is considered a milestone in the development of ultralow power spintronic devices, and it has been a long sought-after goal for electric-field control of magnetoresistance in magnetic tunnel junctions with ultralow power consumption. Operation at cryogenic temperature is detrimental for practical applications To overcome these drawbacks, a scheme of MTJ stacks grown on FE substrate was proposed theoretically[11,28,29], which relied on the recent progress in the room temperature electric-field control of magnetism in FM/FE multiferroic heterostructures[21,30,31,32,33,34,35,36,37,38,39,40]. Through strain-mediated magnetoelectric coupling, MR of MTJs can be electrically controlled by rotating magnetization of the free layer Based on this scheme, an ultrahigh storage capacity, ultralow power dissipation and high-speed MRAM device has been proposed[11]. Room temperature, giant, and non-volatile electrical manipulation of MR in MTJs without a bias magnetic field is highly desirable, while still elusive, though it would be a crucial step towards practical devices such as MRAM

Methods

Results

Conclusion