Altermagnetism and chiral order in a collinear antiferromagnet (MnF 2 )

Journal article

In this work, we study hitherto unknown magnetic properties of a collinear antiferromagnet of widespread interest, because there is intense speculation that the compound is a good atomic altermagnet with spin split electronic bands (manganese fluoride, MnF2). The properties in question are exposed in studies of symmetry informed diffraction patterns for two standard scattering techniques. In one, the magnetically ordered solid is illuminated by x-rays tuned in energy to a Mn atomic resonance, and the radiation in the second technique is a beam of neutrons. With resonant x-ray scattering, intensity of Bragg spots are predicted to change on reversing the handedness of helicity in the primary beam. A change in intensity on switching between left and right handed x-ray circular polarization, say, equates to a magnetic chiral signature for the established magnetic space group. The same technique reveals the order parameter for altermagnetism, which is an axial magnetic octupole (third rank tensor). A multipole with identical discrete symmetries is found in the magnetic Bragg diffraction of neutrons. Moreover, spin-flip patterns from polarized neutron diffraction depend on electronic multipoles that are zero for the nominal 3d5 configuration of Mn2+, which make them excellent tests of the actual electronic structure.

Authors: Lovesey, SW

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Scientific Reports
• Volume: 16
• Issue: 1
• Article number: 14058
• Publication date: 2026-03-18
• Acceptance date: 2026-03-05
• DOI: 10.1038/s41598-026-43686-3
• EISSN: 2045-2322
• ISSN: 2045-2322
• Language: English
• Keywords: Multipole expansion; Diffraction; Bragg's law; Antiferromagnetism; Helicity; Symmetry (geometry); Neutron diffraction; Magnetic structure; Spin (aerodynamics)