=Co, Ni)*

Antiferromagnetism in Fe-based superconductors is characterized by a pair of propagation vectors which may support a number of magnetic phases. Ni- and Co-doping in CaKFe₄As₄ suppresses superconductivity and stabilizes a new antiferromagnetic phase. Thermodynamic, transport, structural and local magnetic probes reveal this phase to be consistent with the hedgehog spin-vortex crystal. Ab initio calculations also indicate a preference for this non-collinear antiferromagnetism which is stabilized by the reduced symmetry of the CaKFe₄As₄ structure.
W. R. Meier et al., arXiv:1706.01067 (2017).