Enhanced Low-Temperature Interfacial Gilbert Damping in Pt/YIG/Pt Trilayer Structures

The temperature-dependent magnetization dynamics in Pt/YIG/Pt trilayer structure is investigated by broadband ferromagnetic resonance (FMR) measurement method. The resonance field shifts toward a lower magnetic field with the decrease in temperature, and subsequently, a substantial increase in the FMR linewidth is obtained. This results in the enhancement of effective Gilbert damping (α
_eff
). The value of α
_eff
is enhanced from 1.1 × 10
^-3
at 300 K to 5.0 × 10
^-3
at 10 K. The origin of this enhancement in α
_eff
value may be interfacial in nature as it is prominent for the lower thickness of yttrium-iron-garnet layer at low temperature. Magnetic anisotropic dispersion at the interface may lead to the increase in inhomogeneous broadening with decreasing temperature.