Antiferromagnetic Structure of CrN

Chromium nitride, crystallizing with the rock salt structure, has been found to be antiferromagnetic with a Néel point of 0°C. The magnetic ordering scheme, as determined by neutron diffraction, is that of the fourth kind, with moments arranged in double ferromagnetic sheets which alternate along a line parallel to a face-diagonal. The structure is orthorhombic below the transition and the space group Pnma has been tentatively assigned. The atomic displacements accompanying the distortion have been partially determined from the diffraction data and are discussed in relation to the magnetic structure. A value of 2.4 μβ has been assigned to the Cr moment; the moment direction is parallel to the $b$ axis of the orthorhombic cell (face-diagonal of the cube).