Room temperature skyrmion ground state stabilized through interlayer exchange coupling

Abstract

Possible magnetic skyrmion device applications motivate the search for structures that extend the stability of skyrmion spin textures to ambient temperature. Here, we demonstrate an experimental approach to stabilize a room temperature skyrmion ground state in chiral magnetic films via exchange coupling across non-magnetic spacer layers. Using spin polarized low-energy electron microscopy to measure all three Cartesian components of the magnetization vector, we image the spin textures in Fe/Ni films. We show how tuning the thickness of a copper spacer layer between chiral Fe/Ni films and perpendicularly magnetized Ni layers permits stabilization of a chiral stripe phase, a skyrmion phase, and a single domain phase. This strategy to stabilize skyrmion ground states can be extended to other magnetic thin film systems and may be useful for designing skyrmion based spintronics devices. V C 2015 AIP Publishing LLC. [http://dx.

Magnetic phases of skyrmion-hostingGaV4S8−ySey(y=0,2Franke1, Huddart2, Hicken3 et al. 2018Phys. Rev. B302323View full textAdd to dashboardCite

“…These include the B20 compounds [5][6][7] and β-Mn-type CoZnMn alloys [8]. In ultra-thin magnetic layers [9,10] and multilayers [11,12] where inversion symmetry is broken at interfaces, Néel-type skyrmions can be stabilized. The formation of Néel-type skyrmions in bulk crystals with polar C nv symmetry was first predicted by Bogdanov and Yablonskii [13] and was recently observed in VOSe 2 O 5 [14], GaV 4 S 8 [15,16], and GaV 4 Se 8 [17].…”

Topological Hall and spin Hall effects in disordered skyrmionic textures

“…The role of real-space topology has continually increased since the experimental discovery of magnetic skyrmions [19][20][21][22][23][24][25][26][27][28][29], which are topologically nontrivial spin textures [30] in non-centro-symmetric ferromagnetic structures. Skyrmions are in pole position in the racetrack memory search, thanks to prominent features that make them the ultimate bit of information [31]: in contrast with magnetic domain walls, skyrmions are topological defects, localized in space, and present a decent robustness against pinning by magnetic defects, enabling current-driven motion at low current density.…”

Interface Dzyaloshinskii-Moriya interaction in the interlayer antiferromagnetic-exchange coupled Pt/CoFeB/Ru/CoFeB systems

“…Recently, Chen et al [20] demonstrates an experimental approach to stabilize a room temperature skyrmion ground state in chiral magnetic films via interlayer exchange coupling (IEC). Indeed, Shawn et al [21] have reported on the direct imaging of chiral spin structures including skyrmions in an exchange coupled thick ferromagnetic Co/Pt multilayer at room temperature with Lorentz transmission electron microscopy.…”