Probing temperature-dependent compensation of the ferrimagnet TmIG

The development of magnon-based devices is of current interest due to the possibility of using spin waves as information carriers, with the advantage of processing information without Joule heating. A particular recent research has been on antiferromagnets, as they exhibit resonances in the range of THz frequencies due to strong exchange interactions, potentially enabling faster processing than ferromagnet-based devices. However, due to the insensitivity to magnetic fields, it is challenging to probe antiferromagnets. Ferrimagnets with two partially compensated magnetic sublattices are a middle ground between ferromagnets and antiferromagnets. Here, we report comprehensive ferromagnetic resonance spectroscopy on the ferrimagnet TmIG across a wide range of temperatures, between 7K and 340K, where the compensation of magnetization and angular momentum is expected. The temperature dependence of the reduced gyromagnetic ratio, effective magnetization, and the Gilbert damping parameters exhibit an abnormality below 170K. However, our data does not show a clear signature of compensation, where the reduced gyromagnetic ratio is expected to approach zero at the magnetization compensation temperature and a singularity at the angular momentum compensation temperature. We speculate that this observation might be attributed to a varying perpendicular anisotropy, defects, or strain in the studied sample.