Interface Charge Induced Multifunctional Manipulations in Metals

Metals are indispensable in modern information technology due to their unique magnetic and electronic properties. However, achieving voltage control of these properties in common metals with large amplitude, reversibility, and durability remains a formidable challenge. Here, we demonstrate giant and reliable tunning of magnetic anisotropy, magnetization, and resistivity in Pt/Co bilayers through an interface‑charge mechanism. By integrating a TiO₂/Pt/Co/TiO₂ heterojunction as positive electrode in a lithium-ion storage device, lithium-ions migrate into the TiO₂ layers during discharge, while electrons are simultaneously injected into the Pt/Co layer through external circuit. The space-separated ions and elections accumulate at TiO₂/Pt and Co/TiO₂ interfaces, generating strong interfacial capacitor effect and high‑density electron accumulation in the metals. In high voltage range (3-2 V), the interfacial capacitance reorients Co anisotropy from perpendicular to in-plane. Further voltage reduction to 0.8 V induces charge accumulation at both interfaces, resulting in 44% decrease in saturation magnetization of Co and 55% reduction in longitudinal resistance of Pt layer. These findings establish the interface-charge as a robust and versatile platform for giant, reversible, and reliable voltage control in metals, opening new opportunities for spintronics, sensing, and neuromorphic computing.