抄録
The magnetic structure of Mn3Si (bcc Fe3Al type crystal structure) at low temperatures has been determined by neutron diffraction using single crystal samples. It is found that Mn3Si has a helical spin structure (Néel temperature 25.8 K) with a wave vector q parallel to one of ⟨111⟩ directions and of magnitude 0.85·1⁄2·2πK111, which is near the boundary of the Brillouin zone. The magnetic structure is either a proper screw or a transversal sinusoidal structure and the magnetic moments at the two Mn sites are μMnI=1.72 μB and μMnII=0.19 μB. The temperature dependence of the magnitude of the wave vector q is similar to that of Cr. From these data the possibility of an itinerant electron antiferromagnetism of Mn3Si is suggested in comparison with the SDW in Cr.
