Temperature-Tuned Spin Dynamics in 2D Ferromagnets: Unraveling Magnetization Precession Across Thermal Landscapes

With the emergence of advanced 2D magnetic systems such as Fe₅GeTe₂, Cr₂Ge₂Te₆, and Fe₃GeTe₂, researchers have uncovered unique magnetic properties, including strong anisotropy and highly tunable spin interactions^1-3. Despite these advances, the thermal effects on spin dynamics and precession remain debatable, posing a significant challenge for their integration into spintronics devices. In this study, we rigorously investigate the temperature-dependent magnetization dynamics across these 2D ferromagnets using ferromagnetic resonance (FMR). Our results reveal that as the temperature decreases, 2D ferromagnets behave completely different from conventional 3D ferromagnets. Fe₅GeTe₂, for example, shows non-trivial topological spin texture at low temperatures resulting in non-linear frequency dependence of the FMR linewidth (Figure 1). Additionally, we measure the proximity effect of these 2D ferromagnets on Ni₈₀Fe₂₀ through spin-torque FMR. Our measurements reveal the Curie temperature of each 2D crystal and uncovered their complicated temperature-dependent spin texture. These findings offer crucial insights into the intricate temperature-dependent behavior of Fe₅GeTe₂, Cr₂Ge₂Te₆, and Fe₃GeTe₂, shedding light on their potential for temperature-sensitive applications in spintronic technologies such as magnetic memory and logic devices.