Interfacial Mixing Effect in a Promising Skyrmionic Material: Ferrimagnetic Mn${}_4$N

Abstract

Interfacial mixing of elements is a well-known phenomenon found in thin film deposition. For thin-film magnetic heterostructures, interfacial compositional inhomogeneities can have drastic effects on the resulting functionalities. As such, care must be taken to characterize the compositional and magnetic properties of thin films intended for device use. Recently, ferrimagnetic Mn${}_4$N thin films have drawn considerable interest due to exhibiting perpendicular magnetic anisotropy, high domain-wall mobility, and good thermal stability. In this study, we employed X-ray photoelectron spectroscopy (XPS) and polarized neutron reflectometry (PNR) measurements to investigate the interfaces of an epitaxially-grown MgO/Mn${}_4$N/Pt trilayer deposited at 450 ${}^{\circ }$C. XPS revealed the thickness of elemental mixing regions of near 5 nm at both interfaces. Using PNR, we found that these interfaces exhibit essentially zero net magnetization at room temperature. Despite the high-temperature deposition at 450 ${}^{\circ }$C, the thickness of mixing regions is comparable to those observed in magnetic films deposited at room temperature. Micromagnetic simulations show that this interfacial mixing should not deter the robust formation of small skyrmions, consistent with a recent experiment. The results obtained are encouraging in terms of the potential of integrating thermally stable Mn${}_4$N into future spintronic devices.

References in corpus (13)

• Anatomy of Dzyaloshinskii-Moriya Interaction at Co/Pt Interfaces
• First-principles investigation of the very large Perpendicular Magnetic Anisotropy at Fe|MgO Interfaces
• Interfacial Dzyaloshinskii-Moriya interaction in perpendicularly-magnetized Pt/Co/AlO${}_x$ ultrathin films measured by Brillouin light spectroscopy
• Interface-generated spin currents
• Current-driven domain wall dynamics in ferrimagnetic Ni-doped Mn4N films : very large domain wall velocities and reversal of motion direction across the magnetic compensation point
• reductus: a stateless Python data-reduction service with a browser frontend
• Tuning interfacial Dzyaloshinskii-Moriya interactions in thin amorphous ferrimagnetic alloys
• Exchange interactions and Curie temperatures of the tetrametal nitrides Cr4N, Mn4N, Fe4N, Co4N, and Ni4N
• Contributions of magnetic structure and nitrogen to perpendicular magnetocrystalline anisotropy in antiperovskite $\epsilon$-Mn${}_4$N
• Nanoscale Magnetic Behavior Localization in Exchange Strength Modulated Ferromagnets
• Tunable Magnetic Skyrmions in Ferrimagnetic Mn${}_4$N
• Rare-earth-free ferrimagnetic Mn4N sub-20 nm thin films as high-temperature spintronic material
• Distributed Error-Function Roughness in Refl1d Reflectometry Fitting Program