R&D: Nonvolatile Voltage-Controlled Magnetization Reversal

NPG Asia Materials has published an article written by Mengli Liu, Wei Du, Hua Su, Huaiwu Zhang, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054, China, Bo Liu, Hao Meng, Key Laboratory of Spintronics Materials, Devices and Systems of Zhejiang Province, Hangzhou, 311305, China, and Xiaoli Tang, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054, China.

Abstract: “Pure voltage-controlled magnetism, rather than a spin current or magnetic field, is the goal for next-generation ultralow power consumption spintronic devices. To advance toward this goal, we report a voltage-controlled nonvolatile 90° magnetization rotation and voltage-assisted 180° magnetization reversal in a spin-valve multiferroic heterostructure. Here, a spin valve with a synthetic antiferromagnetic structure was grown on a (110)-cut Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrate, in which only the magnetic moment of the free layer can be manipulated by an electric field (E-field) via the strain-mediated magnetoelectric coupling effect. As a result of selecting a specified PMN-PT substrate with defect dipoles, nonvolatile and stable magnetization switching was achieved by using voltage impulses. Accordingly, a giant, reversible and nonvolatile magnetoresistance modulation was achieved without the assistance of a magnetic field. In addition, by adopting a small voltage impulse, the critical magnetic field required for complete 180° magnetization reversal of the free layer can be tremendously reduced. A magnetoresistance ratio as large as that obtained by a magnetic field or spin current under normal conditions is achieved. These results indicate that E-field-assisted energy-efficient in-plane magnetization switching is a feasible strategy. This work is significant to the development of ultralow-power magnetoresistive memory and spintronic devices.“