Perpendicular magnetization in sputtered yttrium iron garnet thin films for spin-wave propagation and spin-orbit-torque switching
Phys. Rev. Applied 25, 044077 – Published 27 April, 2026
DOI: https://doi.org/10.1103/32hy-k2mn
Abstract
Yttrium iron garnet (YIG) is known for its extremely low magnetic damping, making it a key material for magnon-based spintronic devices. Although perpendicular magnetic anisotropy (PMA) has been reported in rare-earth-substituted or -doped YIG thin films, its realization in pure YIG remains limited. In this work, we demonstrate that YIG thin films grown on the substituted gadolinium gallium garnet substrates exhibit PMA and a low damping constant. X-ray diffraction measurements revealed an in-plane tensile strain relative to bulk YIG, suggesting that the strain-induced lattice distortion plays an important role in the emergence of PMA. Spin-wave propagation with a forward-volume configuration is investigated using two separated coplanar waveguides and a network analyzer. The measured propagating spin-wave spectra show a coherent propagation over several micrometers with a group velocity of approximately 0.2 km/s. Furthermore, in a heterostructure with a heavy metal layer of Pt, current-induced spin-orbit torque successfully switches the perpendicular magnetization. These results establish sputter-deposited YIG thin films with perpendicular magnetization as a promising platform for studying low-damping spin-wave transport and current-driven magnetization dynamics.
