Magnetic structural analysis of Pt3Fe antiferromagnet by single crystal neutron diffraction

Single-crystal neutron diffraction measurements for a Pt
3
Fe antiferromagnet were performed to determine the detailed magnetic structure below T
N2
= 100 K, where the magnetic structure characterized by the propagation wave vector q
1
= (1/2 1/2 0) and q
2
= (1/2 0 0) are formed. We found that magnetic domain model where both (1/2 1/2 0)-type and (1/2 0 0)-type ordering coexist in a crystal well explains the observed magnetic neutron intensities, but, there is a large difference in the volume fraction of the magnetic domains. This suggests a large spin reorientation at T
N2
where (1/2 1/2 0)-type domains are partially replaced by (1/2 0 0)-type domains.