Gate-controlled magnetic transitions in Fe₃GeTe₂ with lithium ion conducting glass substrate*

Abstract

Since the discovery of magnetism in two dimensions, effective manipulation of magnetism in van der Waals magnets has always been a crucial goal. Ionic gating is a promising method for such manipulation, yet devices gated with conventional ionic liquid may have some restrictions in applications due to the liquid nature of the gate dielectric. Lithium-ion conducting glass-ceramics (LICGC), a solid Li + electrolyte, could be used as a substrate while simultaneously acts as a promising substitute for ionic liquid. Here we demonstrate that the ferromagnetism of Fe 3 GeTe 2 (FGT) could be modulated via LICGC. By applying a voltage between FGT and the back side of LICGC substrate, Li + doping occurs and causes the decrease of the coercive field ( H c ) and ferromagnetic transition temperature ( T c ) in FGT nanoflakes. A modulation efficiency for H c of up to ∼ 24.6% under V g = 3.5 V at T = 100 K is achieved. Our results provide another method to construct electrically-controlled magnetoelectronics, with potential applications in future information technology.