Antiferromagnets have lately appeared in the forefront of spintronics research. Collinear insulating antiferromagnets have exciting applications in magnonic spin transport, while noncollinear antiferromagnets can show for instance anomalous Hall effect or magnon-magnon scattering. In the talk we will detail our investigations of two distinct systems: the noncollinear antiferromagnet family Mn3Z with Z=Sn, Ge and Ga [1]; and hematite (alpha-Fe2O3), a well-known collinear insulating antiferromagnet showing weak ferromagnetism. We use a multiscale description by computing spin model parameters from first principles and assessing the ground state spin configuration and its stability using this model. With this approach we can tackle the nature of the weak ferromagnetic distortion in these antiferromagnets, and provide spin model parameters that can be used in large-scale simulations of magnon dynamics effects.

 

[1]: B Nyári, A Deák, L Szunyogh, Phys. Rev. B 100, 144412 (2019)