Substrate Effects on In-Plane Magnetic Anisotropy and Verwey Transition Temperatures of (100) Magnetite (Fe sub(3)O sub(4)) Films

• Published in: IEEE transactions on magnetics Vol. 52; no. 7; pp. 1 - 4
• Main Authors: Dho, Joonghoe, Kim, Byeonggeon, Ki, Sanghoon
• Format: Journal Article
• Language: English
• Published: 01-07-2016
• Subjects: Diffraction; Epitaxial growth; Film growth; Magnesium oxide; Magnetic anisotropy; Magnetic properties; Substrates; Transition temperature
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2016.2521604

(100) Fe sub(3)O sub(4) films were grown on five different (100)-oriented substrates: MgO, MgAl sub(2)O sub(4) (MAO), (PbMg sub(0.33)Nb sub(0.67)) sub(1-x):(PbTiO sub(3)) sub(x) (PMNT), SrTiO sub(3) (STO), and (LaAlO sub(3)) sub(0.3)(Sr sub(2)AlTaO sub(6)) sub(0.7) (LSAT), to investigate the substrate effects on structural, magnetic, and transport properties of the films. The X-ray diffraction measurements suggested that the epitaxial (100) Fe sub(3)O sub(4) films were grown, although the lattice mismatch between the Fe sub(3)O sub(4) and the substrates varied from +0.25% to -7.8%. Remarkably, the (100) Fe sub(3)O sub(4) films grown on MAO, PMNT, and STO substrates exhibited a distinctive in-plane magnetic anisotropy with the magnetic easy axis along the [010] and [001] directions. In contrast, the (100) Fe sub(3)O sub(4) films on the MgO and LSAT substrates showed a very weak anisotropy in the [011] easy direction. The Verwey transition temperature of the (100) Fe sub(3)O sub(4) film was found to have a minimum value of $\sim 110$ K for MgO and a maximum value of $\sim 122$ K for STO. These results suggest that the magnetic anisotropy and Verwey transition behaviors of the (100) Fe sub(3)O sub(4) film can be tuned by film growth on a specific substrate.