Voltage Control of the Magnetic Anisotropy in Fe_2.7GeTe₂/In₂Se₃ van der Waals Heterostructures

The discovery of van der Waals (vdW) materials has introduced unique opportunities to design unexplored heterostructures by mechanical exfoliation and transfer of various vdW materials. In this work, we fabricate a heterostructure device consisting of vdW ferromagnetic Fe2.7GeTe2 (FGT) and vdW piezoelectric/ferroelectric α-In2Se3 (IS), and observe the FGT magnetic properties as it is voltage-gated by the IS layer. Our magneto-optical Kerr effect (MOKE) measurement shows that the gate voltage can manipulate the magnetic coercivity of FGT, confirming the magnetoelectric interaction between the FGT and IS. The change in FGT magnetic coercivity and anisotropy is attributed to the voltage-controlled strain on the FGT by our Raman spectroscopy and density functional theory (DFT) calculation. Our results pave a way for low-power voltage-driven vdW spintronic devices.