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

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.

Negative Charge-Transfer Energy in SrCoO2.5 Thin Films: An Interplay between O-2p Hole Density, Charge-Transfer Energy, Charge Disproportionation, and Ferromagnetic Ordering

“…Such a unique XRD pattern is the fingerprint of the presence of the BM phase. , It is observed that the Bragg reflections of the 30 nm film appear at slightly lower 2θ values than those of the 70 nm film, as shown clearly in Figure b for the (008) reflection, pointing out toward their different out-of-plane lattice parameters. It is to be noted that a peak appears in the diffraction patterns of the STO substrate and 30 nm thick SCO film (highlighted by the arrows in Figure b) due to Cu Kα 3,4 radiation, and the same is buried under the SCO (008) reflection for the 70 nm thick SCO film. The calculated pseudotetragonal out-of-plane lattice parameters of 30 and 70 nm thick SCO films are about 3.940 and 3.931 Å, respectively.…”

Scaling of the Thermally Induced Sign Inversion of Longitudinal Spin Seebeck Effect in a Compensated Ferrimagnet: Role of Magnetic Anisotropy

“…Furthermore, lattice mismatch between the insulating iron garnet film and substrate induces in‐plane compressive/tensile strain which leads to a magnetoelastic anisotropy favoring an OOP alignment of the magnetic easy axis. [ 54–57 ] The lattice constant of bulk GdIG is a GdIG,bulk = 1.2471 nm, whereas that for single crystalline GSGG substrate is a GdIG,film = 1.2554 nm. [ 58 ] Hence, the GdIG thin film grown epitaxially on a GSGG substrate exhibits an in‐plane lattice constant >1.2471 nm, introducing tensile in‐plane strain in the film, given by .…”

Substrate-Induced Strain Effect on Structural and Magnetic Properties of La0.5Sr0.5CoO3 Films

“…The values of K are obtained from the effective magnetic anisotropy K eff , which is calculated from the area enclosed between the OOP and the IP semi-loops. Thus, K ⊥ = K eff − K S , with , where M S is the saturation magnetization [ 56 ]. K ⊥ values obtained for films with a thickness around 28 nm grown on the four different substrates are compared in Figure 9 .…”

“…From these measurements, both contributions to the perpendicular magnetic anisotropy, i.e., magnetocrystalline and magnetoelastic, cannot be resolved independently. However, a coarse estimation of the magnetoelastic anisotropy using the expression: where λ 100 , μ , and Y denote the magnetostriction, the Poisson ratio, and the Young’s modulus, respectively [ 56 ], offers blurred results. This estimation points to a contribution caused by both magnetoelastic and magnetocrystalline anisotropies without a clear dominance.…”