Dominik Kriegner
In my talk I will present our systematic study of the variation of magnetization and anomalous Hall effect in Mn3−xPtxGa thin films as function of the Pt content and temperature. Since Mn and Pt sharea lattice site and Mn occupies two distinct sites with ferrimagnetic arrangement of the magnetic moments, the system can be driven to a magnetic compensation point [1]. At this point Mn3−xPtxGa can behave similar to the well known antiferromagnetic half Heusler CuMnAs with which is shares its symmetry. CuMnAs was found to have a switchable antiferromagnetic order by a charge current induced staggered Neel spin orbit torque [2]. Recent works also highlighted that thermal effects can complicate the data analysis of aforementioned switching experiments [3].We therefore propose to use Mn3−xPtxGa near the compensation point as a model system to study this spin orbit torque. Here the non-zero magnetization can be used to orient the ferrimagnetic orderby an external magnetic field to prepare the system in a defined state. The current induced torque, (i.e. the variation of the magnetization,) is obtained by homodyne detection and its effect is mapped out for various magnetization orientations. Using this model system we try to contribute to the ongoing discussion about spin orbit torques in antiferromagnets.
[1] R. Sahoo et al., Adv. Mater. 28, 8499 (2016)[2] P. Wadley et al., Science 351, 587 (2016)
[3] C. C. Chiang, et al. Phys. Rev. Lett. 123, 227203 (2019)