The effects of hydrogen absorption on the effective magnetization $\left(4\pi M_{\mathrm{eff}}\right)$, gyromagnetic ratio $\left(\gamma \right)$, Gilbert damping constant $\left({\alpha }_{\mathrm{G}}\right)$, and the inhomogeneous linewidth broadening $\left(\mathrm{\Delta }{H}_0\right)$ in $\mathrm{Py}\left(x\right)/\mathrm{Y}$(16 nm)/Pd(15 nm) trilayer films ($x=2$, 3, 5, 8, 10, 20, 40 nm) were investigated with ferromagnetic resonance (FMR), transmission electron microscopy, and vibrating sample magnetometry. In the presence of a hydrogen atmosphere, the samples show a reduction of their FMR linewidth which is found to stem purely from a reduction of the inhomogeneous linewidth broadening. This is attributed to a rearrangement of atoms at the Py/Y interface in the presence of hydrogen, making the Py/Y interface more homogeneous. In addition, a reduction of $4\pi M_{\mathrm{eff}}$ was seen for all samples in the hydrogen atmosphere which is typical for an increase of the interfacial perpendicular magnetic anisotropy at the Py/Y interface.

• Received 28 April 2021
• Revised 5 August 2021
• Accepted 7 September 2021

DOI:https://doi.org/10.1103/PhysRevB.104.094429