X-ray holographic imaging of magnetic surface spirals in FeGe lamellae

Turnbull, L.A.; Littlehales, M.T.; Wilson, M.N.; Birch, M.T.; Popescu, H.; Jaouen, N.; Verezhak, J.A.T.; Balakrishnan, G.; Hatton, P.D.

Abstract

Isotropic helimagnets are known to host a diverse range of chiral magnetic states. In 2016, Rybakov et al., theorized the presence of a surface-pinned stacked spin spiral phase [F. N. Rybakov et al., New J. Phys. 18, 045002 (2016)], which has yet to be observed experimentally. The phase is characterized by surface spiral periods exceeding the host material's fundamental winding period L D . Here, we present experimental evidence for the observation of this state in lamellae of FeGe using resonant x-ray holographic imaging data and micromagnetic simulations. We find images of FeGe lamellae, exceeding a critical thickness of 300 nm ( 4.3 L D ), exhibit contrast modulations with a field-dependent periodicity of λ ≥ 1.4 L D , consistent with theoretical predictions of the stacked spiral state. The identification of this spiral state has significant implications for the stability of other coexisting spin textures, and will help complete our understanding of helimagnetic systems.

Citation

Turnbull, L., Littlehales, M., Wilson, M., Birch, M., Popescu, H., Jaouen, N., …Hatton, P. (2022). X-ray holographic imaging of magnetic surface spirals in FeGe lamellae. Physical Review B, 106(6), Article 064422. https://doi.org/10.1103/physrevb.106.064422

• Journal Article Type: Article
• Acceptance Date: Jul 28, 2022
• Online Publication Date: Aug 15, 2022
• Publication Date: Aug 1, 2022
• Deposit Date: Nov 29, 2022
• Publicly Available Date: Nov 29, 2022
• Journal: Physical Review B
• Print ISSN: 2469-9950
• Electronic ISSN: 2469-9969
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 106
• Issue: 6
• Article Number: 064422
• DOI: https://doi.org/10.1103/physrevb.106.064422