Investigation of the compensation points in ferrimagnetic insulators

The angular momentum compensation temperature TA is of great importance in spintronics, since fast domain wall motion and fast switching of the magnetization in metallic ferrimagnets can be achieved near TA. Furthermore, spin torque effects are greatly enhanced around TA, which opens new routes for spin-orbit torque applications in low-current-dissipation, spin-current-based heavy metal/ferrimagnetic insulator heterostructures. To exploit the rich physics near TA, an unambiguous determination of TA is essential. We propose to investigate the spin and angular momentum in RE3Fe5O12 (RE=Dy, Tb) single crystal and thin film samples by the element-specific XMCD technique as a function of temperature. By using magneto-optical sum rules we will determine the spin and orbital moment as a function of temperature to determine TM and TA. This will allow us to further investigate the spin transport as well as spin caloric effects in compensated ferromagnetic insulators around TA.