Space-charge Control of Magnetism in Ferromagnetic Metals: Coupling Giant Magnitude and Robust Endurance.

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, we propose a novel space-charge approach which allows us to achieve a modulation of 30.3 emu g -1 under 1.3 V in Co/TiO 2 multilayer granular films. The robust endurance with more than 5,000 cycles was 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 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 towards the development of ionic-magnetic-electric coupled applications. This article is protected by copyright. All rights reserved.