Strain-induced perpendicular magnetic anisotropy and Gilbert damping of Tm3Fe5O12 thin films

Oana Ciubotariu; Anna Semisalova; Kilian Lenz; Manfred Albrecht

doi:10.1038/s41598-019-53255-6

Strain-induced perpendicular magnetic anisotropy and Gilbert damping of Tm₃Fe₅O₁₂ thin films

Sci Rep. 2019 Nov 25;9(1):17474. doi: 10.1038/s41598-019-53255-6.

Authors

Oana Ciubotariu¹, Anna Semisalova^{2

3}, Kilian Lenz², Manfred Albrecht⁴

Affiliations

¹ Institute of Physics, University of Augsburg, Universitätsstraße 1, 86135, Augsburg, Germany. oana-tereza.ciubotariu@physik.uni-augsburg.de.
² Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328, Dresden, Germany.
³ Faculty of Physics, University of Duisburg-Essen, Lotharstraße 1, 47057, Duisburg, Germany.
⁴ Institute of Physics, University of Augsburg, Universitätsstraße 1, 86135, Augsburg, Germany.

Abstract

In the attempt of implementing iron garnets with perpendicular magnetic anisotropy (PMA) in spintronics, the attention turned towards strain-grown iron garnets. One candidate is Tm₃Fe₅O₁₂ (TmIG) which possesses an out-of-plane magnetic easy axis when grown under tensile strain. In this study, the effect of film thickness on the structural and magnetic properties of TmIG films including magnetic anisotropy, saturation magnetization, and Gilbert damping is investigated. TmIG films with thicknesses between 20 and 300 nm are epitaxially grown by pulsed laser deposition on substituted-Gd₃Ga₅O₁₂(111) substrates. Structural characterization shows that films thinner than 200 nm show in-plane tensile strain, thus exhibiting PMA due to strain-induced magnetoelastic anisotropy. However, with increasing film thickness a relaxation of the unit cell is observed resulting in the rotation of the magnetic easy axis towards the sample plane due to the dominant shape anisotropy. Furthermore, the Gilbert damping parameter is found to be in the range of 0.02 ± 0.005.