Tunable Magnetic Skyrmions in Ferrimagnetic Mn${}_4$N

Abstract

Thin films of ferrimagnetic Mn${}_4$N are candidate materials to host magnetic skyrmions that have demonstrated thermal stability up to 450${}^{\circ }$C. However, there are no experimental reports observing skyrmions in this system. Here, we discuss the results of sputter grown 15-17~nm Mn${}_4$N thin films on MgO substrate capped with Pt${}_{1-x}$Cu${}_x$ layers. Vibrating sample magnetometry measurement of out-of-plane hysteresis loops confirmed that magnetic properties are insensitive to the cap layer composition. Imaging based on magnetic force microscopy measurements observed 300 to 50~nm sized skyrmions, as the Cu concentration was increased from $x$ = 0 to 0.9. We performed density functional theory calculations and found that the interfacial Dzyaloshinskii-Moriya interactions (iDMI) follow a trend: Mn${}_4$N/MgO(001) $<$ Cu/Mn${}_4$N(001) $<$ Pt/Mn${}_4$N(001). We infer from these calculations that $x$ in Pt${}_{1-x}$Cu${}_x$ capping layer can serve as a robust tuning knob to tailor the iDMI and control the skyrmion size. This work provides guidance to achieve smaller Néel-type skyrmions in Mn${}_4$N thin films, which is an important step forward for building thermally stable skyrmionic devices.

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Advances in the Physics of Magnetic Skyrmions and Perspective for Technology
• Quantum ESPRESSO toward the exascale
• Observation of room temperature magnetic skyrmions and their current-driven dynamics in ultrathin Co films
• Emergent Phenomena Induced by Spin-Orbit Coupling at Surfaces and Interfaces
• Tunable Room Temperature Magnetic Skyrmions in Ir/Fe/Co/Pt Multilayers
• Anatomy of Dzyaloshinskii-Moriya Interaction at Co/Pt Interfaces
• Predicting the Spin-Lattice Order of Frustrated Systems from First-Principles
• Full phase diagram of isolated skyrmions in a ferromagnet
• Interplay between Kitaev interaction and single ion anisotropy in ferromagnetic CrI${}_3$ and CrGeTe${}_3$ monolayers
• Experimental observation of magnetic bobbers for a new concept of magnetic solid-state memory
• Intrinsic skyrmions in monolayer Janus magnets
• Chiral magnetic textures in Ir/Fe/Co/Pt multilayers: Evolution and topological Hall signature
• Magnetic Skyrmions for Unconventional Computing
• Ab initio methodology for magnetic exchange parameters: \\Generic four-state energy mapping on Heisenberg spin Hamiltonian
• Tuning interfacial Dzyaloshinskii-Moriya interactions in thin amorphous ferrimagnetic alloys
• Contributions of magnetic structure and nitrogen to perpendicular magnetocrystalline anisotropy in antiperovskite $\epsilon$-Mn${}_4$N
• Interfacial Dzyaloshinskii-Moriya Interaction of Antiferromagnetic Materials
• Atomistic perspective of long lifetimes of small skyrmions at room temperature
• Tuning Dzyaloshinskii-Moriya Interaction in Ferrimagnetic GdCo: A First Principles Approach
• Engineering Dzyaloshinskii-Moriya interaction in B20 thin film chiral magnets
• Rare-earth-free ferrimagnetic Mn4N sub-20 nm thin films as high-temperature spintronic material

Cited by in corpus (5)

• Spin-Transfer-Torque Induced Spatially Nonuniform Switching in Ferrimagnets
• Interfacial Mixing Effect in a Promising Skyrmionic Material: Ferrimagnetic Mn${}_4$N
• Ionically-Driven Synthesis and Exchange Bias in Mn${}_4$N/MnN${}_x$ Heterostructures
• Anomalous switching pattern in the ferrimagnetic memory cell
• Positional stability of skyrmions in a racetrack memory with notched geometry