The effect of dynamical compressive and shear strain on magnetic anisotropy in a low symmetry ferromagnetic film

Linnik, T.L.; Kats, V.N.; J�ger, J.; Salasyuk, A.S.; Yakovlev, D.R.; Rushforth, A.W.; Akimov, A.V.; Kalashnikova, A.M.; Bayer, M.; Scherbakov, A.V.

Abstract

Dynamical strain generated upon excitation of a metallic film by a femtosecond laser pulse may become a versatile tool enabling control of magnetic state of thin _lms and nanostructures via inverse magnetostriction on a picosecond time scale. Here we explore two alternative approaches to manipulate magnetocrystalline anisotropy and excite magnetization precession in a low-symmetry _lm of a magnetic metallic alloy galfenol (Fe,Ga) either by injecting picosecond strain pulse into it from a substrate or by generating dynamical strain of complex temporal profile in the film directly. In the former case we realize ultrafast excitation of magnetization dynamics solely by strain pulses. In the latter case optically-generated strain emerged abruptly in the film modifies its magnetocrystalline anisotropy, competing with heat-induced change of anisotropy parameters. We demonstrate that the optically-generated strain remains efficient for launching magnetization precession, when the heat-induced changes of anisotropy parameters do not trigger the precession anymore. We emphasize that in both approaches the ultrafast change of magnetic anisotropy mediating the precession excitation relies on mixed, compressive and shear, character of the dynamical strain, which emerges due to low-symmetry of the metallic film under study.

Citation

Linnik, T., Kats, V., Jäger, J., Salasyuk, A., Yakovlev, D., Rushforth, A., Akimov, A., Kalashnikova, A., Bayer, M., & Scherbakov, A. (2017). The effect of dynamical compressive and shear strain on magnetic anisotropy in a low symmetry ferromagnetic film. Physica Scripta, 92(5), Article 054006. https://doi.org/10.1088/1402-4896/aa6943

• Journal Article Type: Article
• Acceptance Date: Mar 27, 2017
• Publication Date: Apr 25, 2017
• Deposit Date: May 4, 2017
• Publicly Available Date: May 4, 2017
• Journal: Physica Scripta
• Print ISSN: 0031-8949
• Electronic ISSN: 1402-4896
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 92
• Issue: 5
• Article Number: 054006
• DOI: https://doi.org/10.1088/1402-4896/aa6943
• Keywords: Ultrafast laser-induced magnetization dynamics, Picosecond magneto-acoustics, Magnetic anisotropy, Inverse magnetostriction, Optically-induced strain
• Public URL: https://nottingham-repository.worktribe.com/output/857511
• Publisher URL: http://iopscience.iop.org/article/10.1088/1402-4896/aa6943/meta
• Additional Information: This is an author-created, un-copyedited version of an article accepted for publication in Physica Scripta. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://iopscience.iop.org/article/10.1088/1402-4896/aa6943/meta
• Contract Date: May 4, 2017