Voltage control of magnetism in Fe3-xGeTe2/In2Se3 van der Waals ferromagnetic/ferroelectric heterostructures
Jaeun Eom, In Hak Lee, Jung Yun Kee, M.H. Cho, Jeongdae Seo, Hoyoung Suh, Hyung‐Jin Choi, Yumin Sim, Shuzhang Chen, Hye Jung Chang, Seung‐Hyub Baek, C. Petrović, Hyejin Ryu, Chaun Jang, Young Duck Kim, Chan‐Ho Yang, Maeng‐Je Seong, Jin Hong Lee, Se Young Park, Jun Woo Choi
Abstract
Abstract 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- x GeTe 2 and the ferroelectric In 2 Se 3 . It is observed that gate voltages applied to the Fe 3- x GeTe 2 /In 2 Se 3 heterostructure device modulate the magnetic properties of Fe 3- x GeTe 2 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 In 2 Se 3 and Fe 3- x GeTe 2 lattice constants for both voltage polarities. Thus, the voltage-dependent decrease in the Fe 3- x GeTe 2 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.