Antiferromagnetic structure of ζ-MnN0.388 with ‘ϵ-type’ nitrogen ordering

The antiferromagnetic ordering in ζ-MnN0.388 – based on a h.c.p. arrangement of Mn with N on octahedral sites – was examined by neutron diffraction. The relative orientation of the ordered spins agrees with that described previously [Solid State Commun. 23 (1977) 147], though the direction of the magnetic moments relative to the crystallographic axes is found to be different, confirmed by the observation of a magnetic moment component along [001]. The arrangement of the ordered Mn moments is described by the magnetic space group <F>CP2′/m′</F> (am=31/2ah.c.p., bm=ah.c.p., cm=ch.c.p., βm=90°). The magnitude of the moments is 1.68 μB at 298 K and decreases continuously to 0 μB at TN=353.7 K. The moments are tilted by 33° from the monoclinic am axis towards the cm axis within the am–cm plane. The direction of the ordered moments relative to the crystallographic axes remains virtually constant in the investigated temperature range. [Copyright &y& Elsevier]