A giant ME coefficient of 368 Oe V−1 at 1.5 V with good reversibility can be effectively controlled by IL gating in Fe3O4, which could be used to design tunable spintronic devices.

Tuning of magnetic properties by electric field (E-field) has received extensive attentions because it is compact, fast, and energy efficient. Here, multiferroic heterostructures of Fe3O4/Pt/PZN-PT (011) (lead zinc niobate-lead titanate single piezoelectric substrate) were in situ fabricated by atomic layer deposition (ALD) using C10H10Fe and O2 as precursors at a low temperature (400 °C) without a subsequent annealing process in H2 atmosphere, which is beneficial in combining with traditional silicon-based semiconductor technology. The E-field dependence of the magnetic anisotropy was studied systematically by ferromagnetic resonance spectroscopy with the larger tunable in-plane magnetic anisotropy of 152 Oe and 318 Oe obtained along the [100] and [0–11] axes, corresponding to the largest magnetoelectric coupling coefficient of 31.8 Oe.cm/kV. Also, the tunable out-of-plane magnetic anisotropy of 35 Oe was obtained along the [011] axis. The outstanding E-field tuning magnetism in the Fe3O4/Pt/PZN-PT heterostructures offers significant possibilities for novel multiferroic devices.