Space‐Charge Control of Magnetism in Ferromagnetic Metals: Coupling Giant Magnitude and Robust Endurance
Zhaohui Li, Hengjun Liu, Zhiqiang Zhao, Qinghua Zhang, Xingke Fu, Xiangkun Li, Fangchao Gu, Hai Zhong, Yuanyuan Pan, Guihuan Chen, Qinghao Li, Hongsen Li, Yanxue Chen, Lin Gu, Kuijuan Jin, Shishen Yan, Guo‐Xing Miao, Chen Ge, Qiang Li
Abstract
Abstract Ferromagnetic metals show great prospects in ultralow‐power‐consumption spintronic devices, due to their high Curie temperature and robust magnetization. However, there is still a lack of reliable solutions for giant and reversible voltage control of magnetism in ferromagnetic metal films. Here, a novel space‐charge approach is proposed which allows for achieving a modulation of 30.3 emu/g under 1.3 V in Co/TiO 2 multilayer granular films. The robust endurance with more than 5000 cycles is demonstrated. Similar phenomena exist in Ni/TiO 2 and Fe/TiO 2 multilayer granular films, which shows its universality. The magnetic change of 107% in Ni/TiO 2 underlines its potential in a voltage‐driven ON–OFF magnetism. Such giant and reversible voltage control of magnetism can be ascribed to space‐charge effect at the ferromagnetic metals/TiO 2 interfaces, in which spin‐polarized electrons are injected into the ferromagnetic metal layer with the adsorption of lithium‐ions on the TiO 2 surface. These results open the door for a promising method to modulate the magnetization in ferromagnetic metals, paving the way toward the development of ionic‐magnetic‐electric coupled applications.