The magnetic structure of FeNbO4

The antiferromagnetic structure of FeNbO4 was determined by neutron powder diffraction. The magnetic unit cell is doubled with respect to the crystallographic one, k = (1/2 0 0), and the magnetic moments are collinear aligned in the ac-plane with an angle phi a = 75(15)degrees to the a-axis. The Neel temperature of T-N = 38.5(5)K and the extrapolated zero-temperature moment of 1.90(5)mu(B) per Fe-site are fitted to the temperature dependence of the sublattice magnetisation. (C) 2000 Elsevier Science B.V. All rights reserved.