We investigate the voltage control of magnetism in a van der Waals (vdW) heterostructure device consisting of two distinct vdW materials, the ferromagnetic Fe_3-xGeTe₂ and the ferroelectric In₂Se₃. It is observed that gate voltages applied to the Fe_3-xGeTe₂/In₂Se₃ heterostructure device modulate the magnetic properties of Fe_3-xGeTe₂ with significant decrease in coercive field for both positive and negative voltages. Raman spectroscopy on the heterostructure device shows voltage-dependent increase in the in-plane In₂Se₃ and Fe_3-xGeTe₂ lattice constants for both voltage polarities. Thus, the voltage-dependent decrease in the Fe_3-xGeTe₂ coercive field, regardless of the gate voltage polarity, can be attributed to the presence of in-plane tensile strain. This is supported by density functional theory calculations showing tensile-strain-induced reduction of the magnetocrystalline anisotropy, which in turn decreases the coercive field. Our results demonstrate an effective method to realize low-power voltage-controlled vdW spintronic devices utilizing the magnetoelectric effect in vdW ferromagnetic/ferroelectric heterostructures.

我们研究了范德华 (vdW) 异质结构器件中磁性的电压控制，该器件由两种不同的 vdW 材料组成：铁磁 Fe _{3- x} GeTe ₂和铁电 In ₂ Se ₃。观察到施加到Fe _{3- x} GeTe ₂ /In ₂ Se _{3异质结构器件的栅极电压调节Fe 3- x} GeTe ₂的磁性能，并且对于正电压和负电压，矫顽场均显着降低。异质结构器件上的拉曼光谱显示，对于两种电压极性，面内In ₂ Se ₃和Fe _{3- x} GeTe ₂晶格常数均随电压而增加。因此，无论栅极电压极性如何，Fe _{3- x} GeTe ₂矫顽场的电压依赖性减小可归因于面内拉伸应变的存在。这得到了密度泛函理论计算的支持，该计算显示拉伸应变引起磁晶各向异性的减小，进而减小了矫顽场。我们的结果证明了一种利用 vdW 铁磁/铁电异质结构中的磁电效应实现低功耗压控 vdW 自旋电子器件的有效方法。