Contribution from Ising domains overlapping out-of-plane to perpendicular magnetic anisotropy in Mn₄N thin films on MgO(001)

Journal Article · Sun Oct 01 00:00:00 UTC 2017 · Journal of Magnetism and Magnetic Materials

DOI: https://doi.org/10.1016/j.jmmm.2017.03.079 · OSTI ID:1538468

Foley, Andrew  ^[1]; Corbett, Joseph ^[2]; Khan, Alam ^[2]; Richard, Andrea L. ^[2]; Ingram, David C. ^[2]; Smith, Arthur R.  ^[2]; Zhao, Lianshui ^[3]; Gallagher, James C. ^[3]; Yang, Fengyuan ^[3]

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1. Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA; Ohio University
2. Nanoscale and Quantum Phenomena Institute, Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA
3. The Ohio State University, Department of Physics, 191 Woodruff Ave., Columbus, OH 43210, USA

Single phase ε-Mn4N thin and ultrathin films are grown on MgO(001) using molecular beam epitaxy. Reflection high-energy electron diffraction and outof-plane x-ray diffraction measurements are taken for each sample in order to determine the in- and out-of-plane strain for each sample. Vibrating sample magnetometry and superconducting quantum interference device measurements, which are performed on the thin and ultrathin films respectively, are used to plot the magnetization of each sample versus both in- and out-of-plane $$\vec H$$-fields and to determine the magnitude of perpendicular magnetic anisotropy in these films. Three significant components of perpendicular magnetic anisotropy are observed in these films and are attributed to sample strain (1 component) and shape (2 components). Among these components, the most significant component (0.8 to 4.9 $$\frac{Merg}{cm^3}$$) is identified as a second term of shape anisotropy, which possesses a negative linear relationship with sample thickness over the range from 9 nm to 310 nm. Atomic (magnetic) force microscopy measurements show the presence of a surface localized magnetic polarization (22% to 82%), which increases with decreasing thickness, when the net magnetization of the films is zero. The second term of shape anisotropy as well as the surface localized polarization, which each depend on sample thickness, are each regarded as a consequence of Ising domains overlapping out-of-plane in these films.

• Research Organization: Ohio Univ., Athens, OH (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
• Grant/Contract Number: FG02-06ER46317
• OSTI ID: 1538468
• Journal Information: Journal of Magnetism and Magnetic Materials, Journal Name: Journal of Magnetism and Magnetic Materials Journal Issue: C Vol. 439; ISSN 0304-8853
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English