Stability and metastability of skyrmions in thin lamellae of Cu2OSeO3

DOI: 10.1103/PhysRevResearch.2.013096

Authors: M. N. Wilson (Durham University) , M. T. Birch (Durham University; Diamond Light Source) , A. Stefancic (University of Warwick) , A. C. Twitchett-Harrison (University of Cambridge) , G. Balakrishnan (University of Warwick) , T. J. Hicken (Durham University) , R. Fan (Diamond Light Source) , P. Steadman (Diamond Light Source) , P. D. Hatton (University of Durham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Research , VOL 2

State: Published (Approved)
Published: January 2020
Diamond Proposal Number(s): 19421

Abstract: We report small-angle x-ray scattering measurements of the skyrmion lattice in two 200-nm-thick Cu 2 OSeO 3 lamellae aligned with the applied magnetic field parallel to the out of plane [110] or [100] crystallographic directions. Our measurements show that the equilibrium skyrmion phase in both samples is expanded significantly compared to bulk crystals, existing between approximately 30 and 50 K over a wide region of magnetic field. This skyrmion state is elliptically distorted at low fields for the [110] sample, and symmetric for the [100] sample, possibly due to crystalline anisotropy becoming more important at this sample thickness than it is in bulk samples. Furthermore, we find that a metastable skyrmion state can be observed at low temperature by field cooling through the equilibrium skyrmion pocket in both samples. In contrast to the behavior in bulk samples, the volume fraction of metastable skyrmions does not significantly depend on cooling rate. We show that a possible explanation for this is the change in the lowest temperature of the skyrmion state in this lamellae compared to bulk, without requiring different energetics of the skyrmion state.

Journal Keywords: Ferrimagnetism; Helicoidal magnetic texture; Skyrmions; Small-angle x-ray scattering; X-ray resonant magnetic scattering

Diamond Keywords: Skyrmions

Subject Areas: Physics, Materials


Instruments: I10-Beamline for Advanced Dichroism - scattering

Added On: 13/02/2020 10:24

Documents:
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Discipline Tags:

Surfaces Quantum Materials Hard condensed matter - electronic properties Multiferroics Physics Magnetism Materials Science interfaces and thin films

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)