Neutron Diffraction Study of Cr₂As

Abstract

Cr₂As is known as an antiferromagnet with the Néel temperature T_N of 393 K. Its magnetic structure is determined by neutron diffraction by using single crystals as well as powdered samples. The magnetic structure obtained has such a symmetry that any isotropic exchange interaction vanishes between Cr(I) and Cr(II) sublattices, while dipole-dipole like interactions remain finite between them. Values of 0.40±0.08 μ_B and 1.34±0.06 μ_B are obtained for the magnetic moments of Cr(I) and Cr(II) respectively. Contrary to a previous study, it is observed that the magnetizations of Cr(I) and Cr(II) sublattices vanish at the same temperature, T_N. This inconsistency is considered to come from the mis-indexing of lines which are actually due to Cr₂O₃ contamination in the previous work.