Tuning the Magnetic Anisotropy of Fe ₃ O ₄ /Pt Heterostructures Fabricated by Atomic Layer Deposition with In Situ Magnetic Field

Research on tuning the magnetic anisotropy of magnetic heterostructures has been receiving intensive attentions due to their intriguing tuning phenomena. In particular, tuning the magnetic anisotropy by in situ magnetic field during the fabrication process allows a remarkable control of magnetism with energy efficiency and shows significant potential applications for compact, fast, and low-power microwave and electronic devices. In this paper, in situ external out-of-plane and in-plane magnetic fields were applied during the deposition of Fe ₃ O ₄ thin films on Pt substrates by atomic layer deposition at different temperatures (350 °C, 400 °C, and 450 °C). The effects of in situ magnetic field with different directions on the surface morphologies and magnetic properties of F ₃ O ₄ /Pt heterostructures were characterized. It was found that both the out-of-plane and in-plane external magnetic fields tuned the magnetic anisotropy of ferromagnetic Fe ₃ O ₄ when deposited at 400 °C with the maximum resonance field changes of 620 and 1930 Oe along in-plane and out-of-plane directions, respectively. This paper achieves tuning the magnetic properties through in situ magnetic field and provides a possibility for spintronic devices.