Reversible control of magnetization in Fe₃O₄nanoparticles by a supercapacitor

The manipulation of magnetism by electrical means is one of the most intensely pursued research topics of recent times aiming at the development of efficient and low-energy consumption devices in spintronics, microelectronics and bioelectronics. Herein, we successfully tuned the saturated magnetization of Fe₃O₄by a supercapacitor. Through increasing the surface area of magnetic particles and activation of carbon cloth, fully reversible and robust saturation magnetization variation with low power consumption and remarkable switching speed can be realized on Fe₃O₄/ionic liquid interfaces at room temperature. The associated magnetism modulation can be attributed to ionic transition between Fe²⁺and Fe³⁺resulting from both electrostatic and electrochemical doping. This work paves the way for the development of high-performance spintronic devices.