Gate-controlled magnetic transitions in Fe3GeTe2 with lithium ion conducting glass substrate* *Project supported by the National Basic Research Program of China (Grant Nos. 2019YFA0308402 and 2018YFA0305604), the National Natural Science Foundation of China (Grant Nos. 11934001, 11774010, and 11921005), and Beijing Municipal Natural Science Foundation, China (Grant No. JQ20002).

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 Fe3GeTe2 (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.